MegaWizard Plug-In unreadble

Dear all

A few days ago, following problem occurred in my Quartus II V7.2, SP1 running on Win XP

- when I open the MegaWizard Plug-In window, the text isn't readable anymore.

All buttons still function, but are unreadable and so hard to use :-)

Anyone any idea? I have reinstalled Quartus without success.