Lately, it seems as if the graphics card on my Powerbook (G4, the last model made before the MacBook Pro's were released) has been overheating. Whenever I play WoW, or a game of its ilk, I always hear the fan on the graphics card whirring like nuts, with it growing in noise as time goes on. Understandable.
Now, as of yesterday, it's gotten to a point where it's gotten VERY loud and kinda "grindy," I guess. It happened after a 3-hour bout of WoW yesterday, and now happens within 5 minutes of playing it every time. I even tried propping the laptop up on something to give it more ventilation, but it's still whirring like a motherfucking lawnmower. (That mother is probably dead, I'm sure) Is there anything I can do to fix it, or am I forced to rely on my AppleCare?

Also, my Airport card seems not to recognize wireless networks as well as other notebooks. Are there any diagnostics I can run on it?