i seem to be having ram issues. if i play wow for an hour or more, then alt tab to change music or something, my machine grinds to a halt. can anyone point me in a direction

If you think you have physical memory issues then I'd start by running memtest86. This takes hours to run, and does a fairly comprehensive test of the available memory in the machine.

It could just be that you don't have enough free memory and it's having to swap pages in and out to draw the other window: can you open up a terminal window before you start and run top? Then when you alt+tab, check the first few lines; what does it say for buffers and for swap used?

Another possible issue is that WoW could be taking up a lot of your CPU and slowing your system down significantly; there are quite a few reported issues with high CPU usage (under both Wine and Vista). If this is a Wine issue then you may have more luck asking on a Wine forum.

Do you get the same problem if you shut down WoW and then start up another program?

If you have another machine and a local network you could try to ssh into your box. If it doesn't respond then the box is freezed. If you can ssh then the problem might be swap or cpu usage.

If you suspect it's faulty ram then run memtest86.