Basically I just need to know if it is Xfire problem to fix or something you can fix on your end?? If xfire is accessing incorrect place in memory, then it is totally xfire's fault (at least in my opinion). Hence why I get the BSOD sometimes(blue screen of death). As far as I know, the reason you get the BSOD error messages (besides the VxD errors) is because a program that was running accesses memory incorrectly and doesn't have the code built into the program to recover from the error, so then windows OS tries to recover from the error, and if it can't recover from the error, then you get the infamous BSOD. I think it is screwed up xfire files in my opinion, but don't know much about the xfire code nor the avast code.
Would more Dr. Watson logs help you???