diff -Naur kde-workspace-4.7.0-orig/libs/taskmanager/groupmanager.cpp kde-workspace-4.7.0-patched/libs/taskmanager/groupmanager.cpp
--- kde-workspace-4.7.0-orig/libs/taskmanager/groupmanager.cpp	2011-05-20 22:32:08.000000000 +0200
+++ kde-workspace-4.7.0-patched/libs/taskmanager/groupmanager.cpp	2011-08-04 14:27:36.991860818 +0200
@@ -342,6 +342,10 @@
         return;
     }
 
+    foreach (LauncherItem *launcher, launchers) {
+        launcher->removeItemIfAssociated(item);
+    }
+
     if (item->parentGroup()) {
         item->parentGroup()->remove(item);
     }
@@ -416,7 +420,11 @@
     currentActivity = newActivity;
 
     foreach (LauncherItem *item, launchers) {
-        rootGroups[currentActivity][currentDesktop]->add(item);
+        if (item->shouldShow()) {
+            rootGroups[currentActivity][currentDesktop]->add(item);
+        } else {
+            rootGroups[currentActivity][currentDesktop]->remove(item);
+        }
     }
 
     if (onlyGroupWhenFull) {
@@ -454,7 +462,11 @@
     currentDesktop = newDesktop;
 
     foreach (LauncherItem *item, launchers) {
-        rootGroups[currentActivity][currentDesktop]->add(item);
+        if (item->shouldShow()) {
+            rootGroups[currentActivity][currentDesktop]->add(item);
+        } else {
+            rootGroups[currentActivity][currentDesktop]->remove(item);
+        }
     }
 
     if (onlyGroupWhenFull) {
@@ -660,15 +672,10 @@
         return;
     }
 
-    typedef QHash<int, TaskGroup *> Metagroup;
-    foreach (Metagroup metagroup, rootGroups) {
-        foreach (TaskGroup *rootGroup, metagroup) {
-            if (launcher->shouldShow()) {
-                rootGroup->add(launcher);
-            } else {
-                rootGroup->remove(launcher);
-            }
-        }
+    if (launcher->shouldShow()) {
+        rootGroups[currentActivity][currentDesktop]->add(launcher);
+    } else {
+        rootGroups[currentActivity][currentDesktop]->remove(launcher);
     }
 }
 
diff -Naur kde-workspace-4.7.0-orig/libs/taskmanager/launcheritem.cpp kde-workspace-4.7.0-patched/libs/taskmanager/launcheritem.cpp
--- kde-workspace-4.7.0-orig/libs/taskmanager/launcheritem.cpp	2011-05-20 22:32:08.000000000 +0200
+++ kde-workspace-4.7.0-patched/libs/taskmanager/launcheritem.cpp	2011-08-04 14:15:15.938125265 +0200
@@ -120,7 +120,13 @@
 
 bool LauncherItem::shouldShow() const
 {
-    return d->associates.isEmpty();
+    foreach (QObject *obj, d->associates) {
+        TaskItem *item = static_cast<TaskItem *>(obj);
+        if (item && item->isOnCurrentDesktop() && item->task().data()->isOnCurrentActivity()) {
+            return false;
+        }
+    }
+    return true;
 }
 
 void LauncherItemPrivate::associateDestroyed(QObject *obj)