Septa, that "memory could not be written" error happens in Windows as well, but normally only when something is failing. When my old 5700LE started failing due to a bad batch of capacitors being used on it, I'd get that error randomly, and eventually it happened every time that I tried to play. Upon sending the card in and having it repaired for free, it stopped that error. Does WoW do that to you in Windows, or just Wine?