kartu,
Not sure I understand your message, but I'll try to clarify : I actually downgraded by installing PRS650.Flash.Package.orig.zip (a Porkupan russified package that comes with 08100), after erasing PRS+ with the installer trick.
So yes, 08100 is the actual, real version of my firmware, and not the result of my tinkering with XML files... if this was your question, anyway