I had the same problem with a Vortex2 card. I fought and fought with the stupid thing. Tried Win2k drivers, beta drivers, you name it. Never could get it to work. It'd always die after trying to play multiple sounds. Like starting an MP3 and then clicking menus to make the noise. Or even just scrolling through the start menu too fast.
I gave up on it. Sold the Vortex2 to a friend for his wife's computer, and bought a SB Live! Value. No problems with that card. That's the thing with creaf, they're still in business developing drivers that work.