Hi,
As per your information You have sap gui also 7.20 .So it is not old gui problem.
In that thread http://scn.sap.com/thread/1436111 otto gold mention that, same problem he was facing & he solved by this sap notes .
So you can check this thread & follow instructions of this notes .
Note 133903 - Upgrade of graphical Screen Painter
Thanks
Gourav.