diff -r 56cd8111b7f7 -r 41300fa6a67c src/gui/widgets/qdockarealayout_p.h
--- a/src/gui/widgets/qdockarealayout_p.h	Tue Jan 26 12:42:25 2010 +0200
+++ b/src/gui/widgets/qdockarealayout_p.h	Tue Feb 02 00:43:10 2010 +0200
@@ -196,9 +196,10 @@
     QRect rect;
     QMainWindow *mainWindow;
     QList<QDockAreaLayoutItem> item_list;
-
+#ifndef QT_NO_TABBAR
     void updateSeparatorWidgets() const;
     QSet<QWidget*> usedSeparatorWidgets() const;
+#endif //QT_NO_TABBAR
 
 #ifndef QT_NO_TABBAR
     quintptr currentTabId() const;
@@ -233,6 +234,7 @@
     QDockAreaLayout(QMainWindow *win);
     QDockAreaLayoutInfo docks[4];
     int sep; // separator extent
+    bool fallbackToSizeHints; //determines if we should use the sizehint for the dock areas (true until the layout is restored or the central widget is set)
     mutable QVector<QWidget*> separatorWidgets;
 
     bool isValid() const;
@@ -278,7 +280,9 @@
                             const QPoint &mouse) const;
     QRegion separatorRegion() const;
     int separatorMove(const QList<int> &separator, const QPoint &origin, const QPoint &dest);
+#ifndef QT_NO_TABBAR
     void updateSeparatorWidgets() const;
+#endif //QT_NO_TABBAR
 
     QLayoutItem *itemAt(int *x, int index) const;
     QLayoutItem *takeAt(int *x, int index);
@@ -292,9 +296,10 @@
     QRect gapRect(const QList<int> &path) const;
 
     void keepSize(QDockWidget *w);
-
+#ifndef QT_NO_TABBAR
     QSet<QTabBar*> usedTabBars() const;
     QSet<QWidget*> usedSeparatorWidgets() const;
+#endif //QT_NO_TABBAR
 };
 
 QT_END_NAMESPACE