diff -r dee5afe5301f -r 3f74d0d4af4c src/gui/painting/qtransform.h
--- a/src/gui/painting/qtransform.h	Mon Mar 15 12:43:09 2010 +0200
+++ b/src/gui/painting/qtransform.h	Thu Apr 08 14:19:33 2010 +0300
@@ -293,7 +293,8 @@
     affine._dx  *= num;
     affine._dy  *= num;
     m_33        *= num;
-    m_dirty     |= TxScale;
+    if (m_dirty < TxScale)
+        m_dirty = TxScale;
     return *this;
 }
 inline QTransform &QTransform::operator/=(qreal div)
@@ -316,7 +317,7 @@
     affine._dx  += num;
     affine._dy  += num;
     m_33        += num;
-    m_dirty     |= TxProject;
+    m_dirty     = TxProject;
     return *this;
 }
 inline QTransform &QTransform::operator-=(qreal num)
@@ -332,7 +333,7 @@
     affine._dx  -= num;
     affine._dy  -= num;
     m_33        -= num;
-    m_dirty     |= TxProject;
+    m_dirty     = TxProject;
     return *this;
 }