The same problem here
World of Warcraft random freeze.
MS Win Xp sp2
GF 7900 GT GV-NX79T255DP-RH
PSU 560 Watt Chieftec
All drivers - latest, no o/c. I was trying all, reinstall all, new/old drivers etc.
Only way to make my game run normal is to add "-opengl" to WoW.exe (7-14 fps but game is stable, no freeze).
I don't know what can i do