>I have a couple of clients who recently have installed WinXP. When my FPD25 apps start as usual in the Full Screen mode the colors go haywire and nothing is readable (general green/yellow tone).

Have you played with the compatibility settings? View the properties of the app (in Windows Explorer) and click on "Compatiblity". You might want to tell it to Disable Visual Themes, use 256 colors, and make the app think its Windows 95.

Let me know if any of these work for you.