diff -r 2c63c486cc96 java.source/src/org/netbeans/modules/java/source/usages/RepositoryUpdater.java
--- a/java.source/src/org/netbeans/modules/java/source/usages/RepositoryUpdater.java	Thu Dec 11 11:12:03 2008 +0100
+++ b/java.source/src/org/netbeans/modules/java/source/usages/RepositoryUpdater.java	Thu Dec 11 11:21:07 2008 +0100
@@ -617,6 +617,7 @@
         if (!noscan) {
             synchronized (this) {
                 this.noSubmited++;
+                LOGGER.log(Level.WARNING, "submit()+: " + this.noSubmited);
             }
             final CompileWorker cw = new CompileWorker (work);
             JavaSource.Priority p;
@@ -771,8 +772,14 @@
         Reference<Task> taskRef = url2CompileWithDepsTask.get(root);
         Task t = taskRef != null ? taskRef.get() : null;
         Collection<File> storedFiles;
+        Boolean can = null;
+
+        LOGGER.log(Level.WARNING, "t: " + t);
         
-        if (t == null || !t.cancel()) {
+        if (t == null || (can = !t.cancel())) {
+            if (can != null) {
+                 LOGGER.log(Level.WARNING, "canceling: " + System.identityHashCode(t) + ", " + can);
+            }
             if (lockRU == 0 || t != null) {
                 storedFiles = new LinkedHashSet<File>();
                 url2CompileWithDeps.put(root, storedFiles);
@@ -788,6 +795,7 @@
                 //the task either does not exist, or has been already started - create new one:
                 LOGGER.log(Level.FINER, "creating a new task for root: {0}", root.toExternalForm());
                 final Collection<File> storedFilesFin = storedFiles;
+                final Task[] tt = new Task[1];
                 t = WORKER.create(new Runnable() {
                     public void run() {
                         synchronized (RepositoryUpdater.this) {
@@ -795,25 +803,50 @@
                         }
                         submit(Work.compileWithDeps(root, storedFilesFin));
                         noSubmited--;
+                        LOGGER.log(Level.WARNING, "assureCompiledWithDeps-: " + noSubmited + ":" + System.identityHashCode(tt[0]));
                     }
                 });
-                url2CompileWithDepsTask.put(root, new WeakReference<Task>(t));
+                tt[0] = t;
+                class WR extends WeakReference<Task> implements Runnable {
+
+                    long l;
+                    public WR(Task t) {
+                        super(t, Utilities.activeReferenceQueue());
+                        l = System.identityHashCode(t);
+                    }
+
+                    public void run() {
+                         LOGGER.log(Level.WARNING, "GCing: " + l);
+                    }
+
+                }
+                url2CompileWithDepsTask.put(root, new WR(t));
                 compileScheduled++;
-                noSubmited++;
+                LOGGER.log(Level.WARNING, "assureCompiledWithDeps+: " + noSubmited + ":" + System.identityHashCode(t));
             } else {
                 url2CompileWithDepsTask.remove(root);
             }
         } else {
             storedFiles = url2CompileWithDeps.get(root);
+            if (can != null) {
+                 LOGGER.log(Level.WARNING, "2. canceling: " + System.identityHashCode(t) + ", " + can);
+            }
+            if (t != null) {
+                noSubmited--;
+            }
         }
         
         assert storedFiles != null;
 
         storedFiles.add(file);
-        
+
+        LOGGER.log(Level.WARNING, "lockRU: " + lockRU);
+
         if (lockRU > 0) {
             compileWithDepsToBeScheduled = true;
         } else {
+            LOGGER.log(Level.WARNING, "scheduling: " + System.identityHashCode(t));
+            noSubmited++;
             t.schedule(DELAY);
         }
     }
@@ -914,9 +947,11 @@
                         public void run() {
                             submit(Work.compileWithDeps(root, storedFilesFin));
                             noSubmited--;
+                            LOGGER.log(Level.WARNING, "unlockRU-: " + noSubmited);
                         }
                     });
                     noSubmited++;
+                    LOGGER.log(Level.WARNING, "unlockRU+: " + noSubmited);
                     url2CompileWithDepsTask.put(root, new WeakReference<Task>(t));
                 }
 
@@ -1302,7 +1337,7 @@
                     boolean continuation = false;
                     try {
                     final WorkType type = work.getType();                        
-                    LOGGER.finer ("Request for: " + type);      //NOI18N
+                    LOGGER.warning("Request for: " + type);      //NOI18N
                     switch (type) {
                         case FILTER_CHANGED:
                         {
@@ -1614,6 +1649,7 @@
                     if (!continuation) {
                         synchronized (RepositoryUpdater.this) {
                             RepositoryUpdater.this.noSubmited--;
+                            LOGGER.log(Level.WARNING, "compileWorker.run()-: " + noSubmited);
                             if (RepositoryUpdater.this.noSubmited == 0) {
                                 RepositoryUpdater.this.notifyAll();
                             }