Can't say I really have any issues like this. I did however notice some kind of memory leak introduced in a recent version of wine or WoW. Over say 4 hours, the WoW process eats up to about 1GB of RAM. That just continues with longer gameplay. Even still, I don't experience any performance degredation. I'd be suggesting checking the obvious... does glxgears performance suffer too when WoW performance suffers? If it does, it's your graphics card or associated drivers. Perhaps the fan's duty cycle is too low leading to gradually higher temps? How about CPU usage? Mine is constantly at about 100% usage of one core (got 3). Does it decrease or increase for you?
