Some things you can try:
1) Have you upgraded your PDOX from 7 to 8? If it's true, then you can try to remove PDOX8, with all his traces in the registry and in the Settings folder, removing all traces of it, then reinstalling.
2) Have you got nonstandard windows interface fonts settings? Try resetting them to a standard combination, and disable all themes if you're using WinXP.
3) Have you loaded your forms in design mode in Pdox8 and saved them back? Try it!
Bye!