diff --git a/effects/dialogparent/dialogparent.cpp b/effects/dialogparent/dialogparent.cpp
index ea79641b2f..d5a8d3fcb6 100644
--- a/effects/dialogparent/dialogparent.cpp
+++ b/effects/dialogparent/dialogparent.cpp
@@ -3,6 +3,7 @@
  This file is part of the KDE project.
 
 Copyright (C) 2006 Rivo Laks <rivolaks@hot.ee>
+Copyright (C) 2011 Thomas Lübking <thomas.luebking@web.de>
 
 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
@@ -35,76 +36,63 @@ DialogParentEffect::DialogParentEffect()
 void DialogParentEffect::reconfigure(ReconfigureFlags)
 {
     // How long does it take for the effect to get it's full strength (in ms)
-    changeTime = animationTime(200);
+    changeTime = animationTime(300);
 }
 
 void DialogParentEffect::prePaintWindow(EffectWindow* w, WindowPrePaintData& data, int time)
 {
-    // Check if this window has a modal dialog and change the window's
-    //  effect's strength accordingly
-    bool hasDialog = w->findModal() != NULL;
-    if (hasDialog) {
-        // Increase effect strength of this window
-        effectStrength[w] = qMin(1.0, effectStrength[w] + time / changeTime);
-    } else {
-        effectStrength[w] = qMax(0.0, effectStrength[w] - time / changeTime);
+    QMap<EffectWindow*, float>::iterator it = effectStrength.find(w);
+    if (it != effectStrength.end()) {
+        if (!w->findModal()) {
+            *it -= time/changeTime;
+            if (*it <= 0.0f)
+                effectStrength.erase(it);
+        }
+        else if (*it < 1.0f)
+            *it = qMin(1.0f, *it + time/changeTime);
     }
-
-    // Call the next effect
     effects->prePaintWindow(w, data, time);
 }
 
 void DialogParentEffect::paintWindow(EffectWindow* w, int mask, QRegion region, WindowPaintData& data)
 {
-    double s = effectStrength[w];
+    const float s = effectStrength.value(w, 0.0);
     if (s > 0.0f) {
-        // Brightness will be within [1.0; 0.6]
-        data.brightness *= (1.0 - s * 0.4);
-        // Saturation within [1.0; 0.4]
-        data.saturation *= (1.0 - s * 0.6);
+        data.brightness *= (1.0f - 0.4*s); // [1.0; 0.6]
+        data.saturation *= (1.0f - 0.6*s); // [1.0; 0.4]
     }
-
-    // Call the next effect.
     effects->paintWindow(w, mask, region, data);
 }
 
 void DialogParentEffect::postPaintWindow(EffectWindow* w)
 {
-    double s = effectStrength[w];
+    const float s = effectStrength.value(w, 0.0);
+    if (s > 0.0f && s < 1.0f) // not done yet
+        w->addRepaintFull();
 
-    // If strength is between 0 and 1, the effect is still in progress and the
-    //  window has to be repainted during the next pass
-    if (s > 0.0 && s < 1.0)
-        w->addRepaintFull(); // trigger next animation repaint
-
-    // Call the next effect.
-    effects->postPaintWindow(w);
+    effects->postPaintWindow( w );
 }
 
 void DialogParentEffect::slotWindowActivated(EffectWindow* w)
 {
-    // If this window is a dialog, we need to repaint it's parent window, so
-    //  that the effect could be run for it
-    // Set the window to be faded (or NULL if no window is active).
     if (w && w->isModal()) {
-        // w is a modal dialog
         EffectWindowList mainwindows = w->mainWindows();
-        foreach (EffectWindow * parent, mainwindows)
-        parent->addRepaintFull();
+        foreach (EffectWindow* parent, mainwindows) {
+            if (!effectStrength.contains(parent))
+                effectStrength[parent] = 0.0;
+            parent->addRepaintFull();
+        }
     }
 }
 
 void DialogParentEffect::slotWindowClosed(EffectWindow* w)
 {
-    // If this window is a dialog, we need to repaint it's parent window, so
-    //  that the effect could be run for it
-    // Set the window to be faded (or NULL if no window is active).
     if (w && w->isModal()) {
-        // w is a modal dialog
         EffectWindowList mainwindows = w->mainWindows();
-        foreach (EffectWindow * parent, mainwindows)
-        parent->addRepaintFull();
+        foreach(EffectWindow* parent, mainwindows)
+            parent->addRepaintFull(); // brighten up
     }
+    effectStrength.remove(w);
 }
 
 } // namespace
diff --git a/effects/dialogparent/dialogparent.h b/effects/dialogparent/dialogparent.h
index 1514e7ae6a..c966f60cce 100644
--- a/effects/dialogparent/dialogparent.h
+++ b/effects/dialogparent/dialogparent.h
@@ -53,8 +53,8 @@ protected:
     bool hasModalWindow(EffectWindow* t);
 private:
     // The progress of the fading.
-    QHash<EffectWindow*, double> effectStrength;
-    double changeTime;
+    QMap<EffectWindow*, float> effectStrength;
+    float changeTime;
 };
 
 } // namespace