diff -r 79de32ba3296 -r 89e065397ea6 src/gui/styles/qstylesheetstyle.cpp
--- a/src/gui/styles/qstylesheetstyle.cpp	Fri May 14 16:40:13 2010 +0300
+++ b/src/gui/styles/qstylesheetstyle.cpp	Thu May 27 13:40:48 2010 +0300
@@ -1533,7 +1533,9 @@
     QHash<const void *, StyleSheet>::const_iterator defaultCacheIt = styleSheetCache->constFind(baseStyle());
     if (defaultCacheIt == styleSheetCache->constEnd()) {
         defaultSs = getDefaultStyleSheet();
-        styleSheetCache->insert(baseStyle(), defaultSs);
+        QStyle *bs = baseStyle();
+        styleSheetCache->insert(bs, defaultSs);
+        QObject::connect(bs, SIGNAL(destroyed(QObject*)), this, SLOT(styleDestroyed(QObject*)), Qt::UniqueConnection);
     } else {
         defaultSs = defaultCacheIt.value();
     }
@@ -2660,6 +2662,11 @@
     autoFillDisabledWidgets->remove((const QWidget *)o);
 }
 
+void QStyleSheetStyle::styleDestroyed(QObject *o)
+{
+    styleSheetCache->remove(o);
+}
+
 /*!
  *  Make sure that the cache will be clean by connecting destroyed if needed.
  *  return false if the widget is not stylable;