diff --git a/jode/jode/flow/CatchBlock.java b/jode/jode/flow/CatchBlock.java
index 0fdd650..133a1cf 100644
--- a/jode/jode/flow/CatchBlock.java
+++ b/jode/jode/flow/CatchBlock.java
@@ -48,8 +48,6 @@ public class CatchBlock extends StructuredBlock {
     public CatchBlock(Type type, LocalInfo local) {
         exceptionType = type;
         exceptionLocal = local;
-	if (local != null)
-	    used.addElement(exceptionLocal);
     }
 
     public Type getExceptionType() {
@@ -115,13 +113,19 @@ public class CatchBlock extends StructuredBlock {
     }
 
     public void removePush() {
-	if (pushedLocal != null) {
+	if (pushedLocal != null)
 	    exceptionLocal = pushedLocal;
-	    used.addElement(pushedLocal);
-	}
 	super.removePush();
     }
 
+    public VariableSet propagateUsage() {
+	if (used == null)
+	    used = new VariableSet(); /*XXX*/
+	if (exceptionLocal != null)
+	    used.addElement(exceptionLocal);
+	return super.propagateUsage();
+    }
+
     /**
      * Print the code for the declaration of a local variable.
      * @param writer The tabbed print writer, where we print to.
diff --git a/jode/jode/flow/ConditionalBlock.java b/jode/jode/flow/ConditionalBlock.java
index 4ef8edf..a47a5f7 100644
--- a/jode/jode/flow/ConditionalBlock.java
+++ b/jode/jode/flow/ConditionalBlock.java
@@ -112,7 +112,7 @@ public class ConditionalBlock extends InstructionContainer {
 
     public void removePush() {
 	if (stack != null)
-	    instr = stack.mergeIntoExpression(instr, used);
+	    instr = stack.mergeIntoExpression(instr);
 	trueBlock.removePush();
     }
 
diff --git a/jode/jode/flow/CreateCheckNull.java b/jode/jode/flow/CreateCheckNull.java
index 6d81e3b..185f28e 100644
--- a/jode/jode/flow/CreateCheckNull.java
+++ b/jode/jode/flow/CreateCheckNull.java
@@ -63,7 +63,6 @@ public class CreateCheckNull {
 
 	LocalInfo li = new LocalInfo();
 	ic.setInstruction(new CheckNullOperator(Type.tUObject, li));
-	ic.used.addElement(li);
 	last.replace(last.outer);
         return true;
     }
@@ -94,7 +93,6 @@ public class CreateCheckNull {
 	LocalInfo li = new LocalInfo();
 	InstructionContainer ic = 
 	    new InstructionBlock(new CheckNullOperator(Type.tUObject, li));
-	ic.used.addElement(li);
 	ifBlock.flowBlock.removeSuccessor(ifBlock.thenBlock.jump);
 	ic.moveJump(ifBlock.jump);
 	if (last == ifBlock) {
diff --git a/jode/jode/flow/IfThenElseBlock.java b/jode/jode/flow/IfThenElseBlock.java
index a010277..c41b7cc 100644
--- a/jode/jode/flow/IfThenElseBlock.java
+++ b/jode/jode/flow/IfThenElseBlock.java
@@ -125,12 +125,19 @@ public class IfThenElseBlock extends StructuredBlock {
     
     public void removePush() {
 	if (condStack != null)
-	    cond = condStack.mergeIntoExpression(cond, used);
+	    cond = condStack.mergeIntoExpression(cond);
         thenBlock.removePush();
 	if (elseBlock != null)
 	    elseBlock.removePush();
     }
 
+    public VariableSet propagateUsage() {
+	if (used == null)
+	    used = new VariableSet(); /*XXX*/
+	cond.fillInGenSet(null, used);
+	return super.propagateUsage();
+    }
+
     /**
      * Print the source code for this structured block.  This may be
      * called only once, because it remembers which local variables
diff --git a/jode/jode/flow/InstructionBlock.java b/jode/jode/flow/InstructionBlock.java
index 099cd5b..0455a5b 100644
--- a/jode/jode/flow/InstructionBlock.java
+++ b/jode/jode/flow/InstructionBlock.java
@@ -77,13 +77,12 @@ public class InstructionBlock extends InstructionContainer {
 
     public void removePush() {
 	if (stack != null)
-	    instr = stack.mergeIntoExpression(instr, used);
+	    instr = stack.mergeIntoExpression(instr);
 	if (pushedLocal != null) {
 	    Expression store = new StoreInstruction
 		(new LocalStoreOperator
 		 (pushedLocal.getType(), pushedLocal)).addOperand(instr);
 	    instr = store;
-	    used.addElement(pushedLocal);
 	}
 	super.removePush();
     }
diff --git a/jode/jode/flow/InstructionContainer.java b/jode/jode/flow/InstructionContainer.java
index 912c243..f647625 100644
--- a/jode/jode/flow/InstructionContainer.java
+++ b/jode/jode/flow/InstructionContainer.java
@@ -33,19 +33,16 @@ public abstract class InstructionContainer extends StructuredBlock {
 
     public InstructionContainer(Expression instr) {
         this.instr = instr;
-	if (instr != null)
-	    instr.fillInGenSet(null, used);
     }
 
     public InstructionContainer(Expression instr, Jump jump) {
 	this(instr);
         setJump(jump);
-    }
-
-    public void setJump(Jump jump) {
-	super.setJump(jump);
-	jump.gen.add(used);
-	jump.kill.add(used);
+	if (instr != null) {
+	    VariableSet gen = new VariableSet();
+	    instr.fillInGenSet(null, jump.gen);
+	    instr.fillInGenSet(null, jump.kill);
+	}
     }
 
     /** 
@@ -72,6 +69,14 @@ public abstract class InstructionContainer extends StructuredBlock {
 	    instr.fillInGenSet(in, gen);
     }
 
+    public VariableSet propagateUsage() {
+	if (used == null)
+	    used = new VariableSet(); /*XXX*/
+	if (instr != null)
+	    instr.fillInGenSet(null, used);
+	return super.propagateUsage();
+    }
+
     public boolean doTransformations() {
         StructuredBlock last = flowBlock.lastModified;
         return CreateNewConstructor.transform(this, last)
diff --git a/jode/jode/flow/RetBlock.java b/jode/jode/flow/RetBlock.java
index 2dfe12f..18e6171 100644
--- a/jode/jode/flow/RetBlock.java
+++ b/jode/jode/flow/RetBlock.java
@@ -35,7 +35,6 @@ public class RetBlock extends StructuredBlock {
 
     public RetBlock(LocalInfo local) {
 	this.local = local;
-	used.addElement(local);
     }
 
     /**
@@ -59,6 +58,13 @@ public class RetBlock extends StructuredBlock {
 	return null;
     }
 
+    public VariableSet propagateUsage() {
+	if (used == null)
+	    used = new VariableSet(); /*XXX*/
+	used.addElement(local);
+	return super.propagateUsage();
+    }
+
     public void dumpInstruction(jode.decompiler.TabbedPrintWriter writer) 
         throws java.io.IOException 
     {
diff --git a/jode/jode/flow/ReturnBlock.java b/jode/jode/flow/ReturnBlock.java
index b6fd5d3..88605dc 100644
--- a/jode/jode/flow/ReturnBlock.java
+++ b/jode/jode/flow/ReturnBlock.java
@@ -60,7 +60,7 @@ public class ReturnBlock extends InstructionContainer {
 
     public void removePush() {
 	if (stack != null)
-	    instr = stack.mergeIntoExpression(instr, used);
+	    instr = stack.mergeIntoExpression(instr);
     }
 
     /**
diff --git a/jode/jode/flow/SequentialBlock.java b/jode/jode/flow/SequentialBlock.java
index 1f6255d..c84042e 100644
--- a/jode/jode/flow/SequentialBlock.java
+++ b/jode/jode/flow/SequentialBlock.java
@@ -168,7 +168,9 @@ public class SequentialBlock extends StructuredBlock {
      * block (this is <i>not</i> the used set).
      */
     public VariableSet propagateUsage() {
-        VariableSet allUse = (VariableSet) used.clone();
+	if (used == null)
+	    used = new VariableSet();/*XXX*/
+        VariableSet allUse = new VariableSet();
 	VariableSet childUse0 = subBlocks[0].propagateUsage();
 	VariableSet childUse1 = subBlocks[1].propagateUsage();
 	/* All variables used somewhere inside both sub blocks, are
diff --git a/jode/jode/flow/StructuredBlock.java b/jode/jode/flow/StructuredBlock.java
index 471c26c..7e49248 100644
--- a/jode/jode/flow/StructuredBlock.java
+++ b/jode/jode/flow/StructuredBlock.java
@@ -64,9 +64,9 @@ public abstract class StructuredBlock {
 
     /**
      * The variable set containing all variables that are used in
-     * this block.
+     * this block.  You must set this, before calling super.propagateUsage.
      */
-    VariableSet used = new VariableSet();
+    VariableSet used;
 
     /**
      * The variable set containing all variables we must declare.
@@ -210,16 +210,16 @@ public abstract class StructuredBlock {
      * will be moved to this block (may be this).  
      */
     void moveDefinitions(StructuredBlock from, StructuredBlock sub) {
-        while (from != sub && from != this) {
-            used.unionExact(from.used);
-            from.used.removeAllElements();
-            StructuredBlock[] subs = from.getSubBlocks();
-            if (subs.length == 0)
-                return;
-            for (int i=0; i<subs.length - 1; i++)
-                moveDefinitions(subs[i], sub);
-            from = subs[subs.length-1];
-        }
+//          while (from != sub && from != this) {
+//              used.unionExact(from.used);
+//              from.used.removeAllElements();
+//              StructuredBlock[] subs = from.getSubBlocks();
+//              if (subs.length == 0)
+//                  return;
+//              for (int i=0; i<subs.length - 1; i++)
+//                  moveDefinitions(subs[i], sub);
+//              from = subs[subs.length-1];
+//          }
     }
 
     /**
@@ -349,6 +349,8 @@ public abstract class StructuredBlock {
      * block (this is <i>not</i> the used set).  
      */
     public VariableSet propagateUsage() {
+	if (used == null)
+	    used = new VariableSet(); /*XXX*/
         StructuredBlock[] subs = getSubBlocks();
         VariableSet allUse = (VariableSet) used.clone();
         for (int i=0; i<subs.length; i++) {
diff --git a/jode/jode/flow/SwitchBlock.java b/jode/jode/flow/SwitchBlock.java
index b270628..6561222 100644
--- a/jode/jode/flow/SwitchBlock.java
+++ b/jode/jode/flow/SwitchBlock.java
@@ -120,7 +120,7 @@ implements BreakableBlock {
 
     public void removePush() {
 	if (exprStack != null)
-	    instr = exprStack.mergeIntoExpression(instr, used);
+	    instr = exprStack.mergeIntoExpression(instr);
 	super.removePush();
     }
 
@@ -183,6 +183,13 @@ implements BreakableBlock {
         return getNextFlowBlock();
     }
 
+    public VariableSet propagateUsage() {
+	if (used == null)
+	    used = new VariableSet(); /*XXX*/
+	instr.fillInGenSet(null, used);
+	return super.propagateUsage();
+    }
+
     public void dumpInstruction(TabbedPrintWriter writer) 
 	throws java.io.IOException
     {
@@ -191,7 +198,9 @@ implements BreakableBlock {
             writer.println(label+":");
             writer.tab();
         }
-        writer.print("switch ("+instr+")");
+        writer.print("switch (");
+	instr.dumpExpression(writer);
+	writer.print(")");
 	writer.openBrace();
 	for (int i=0; i < caseBlocks.length; i++)
 	    caseBlocks[i].dumpSource(writer);
diff --git a/jode/jode/flow/TransformExceptionHandlers.java b/jode/jode/flow/TransformExceptionHandlers.java
index 6dfe263..5482731 100644
--- a/jode/jode/flow/TransformExceptionHandlers.java
+++ b/jode/jode/flow/TransformExceptionHandlers.java
@@ -314,7 +314,6 @@ public class TransformExceptionHandlers {
 					store.getSubExpressions()[1];
 				    ret.setInstruction(expr);
                                     ret.replace(ret.outer);
-                                    ret.used.removeElement(local);
                                 }
                             } catch(ClassCastException ex) {
                                 /* didn't succeed */
diff --git a/jode/jode/flow/VariableStack.java b/jode/jode/flow/VariableStack.java
index ba1abb9..b465663 100644
--- a/jode/jode/flow/VariableStack.java
+++ b/jode/jode/flow/VariableStack.java
@@ -98,12 +98,12 @@ public class VariableStack {
 	return first;
     }
 
-    public Expression mergeIntoExpression(Expression expr, VariableSet used) {
+    public Expression mergeIntoExpression(Expression expr) {
 	/* assert expr.getFreeOperandCount() == stackMap.length */
 
 	for (int i = stackMap.length-1; i >= 0; i--) {
-	    if (!used.contains(stackMap[i]))
-		used.addElement(stackMap[i]);
+//  	    if (!used.contains(stackMap[i]))
+//  		used.addElement(stackMap[i]);
 	    expr = expr.addOperand
 		(new LocalLoadOperator(stackMap[i].getType(), null, 
 				       stackMap[i]));