All right, old bill.

My PC: Like Said
Win XP SP2
1024 MB RAM
ATI Radeon 9800 Pro with Catalist 5.5 drivers
Creative SB Audigy with latest drivers (21.10.2003)
GS 6.31.4 (also I´m Beta tester with 6.32.8 where the same error comes)

I have installed GS with the Trial Version from the download page and installed my key(6.00.02??). The update to 6.31.4 was succesful and no files are write protected.

Also I have the windows firewall active and no virus!!