>Or is it really true, that i have to buy a new (older) version (2.6)
>of Foxpro to install the microsoft patch ?

Try the international version of our patch, IPatchFP.exe, as referenced in MS KnowledgeBase article http://support.microsoft.com/support/kb/articles/Q240/9/82.ASP. It is not supported or tested on FPW 2.5, but you may be able to get it to work.