I have a USB 2.0 card marked FS-MEG-ALI, which functioned well in its previous installation...in a 500 MHz AMD machine that dragged WinXP around like Marley's Chains. In the new machine it (a) causes it to turn on if inserted into the slot when turned off, and (b) the computer will not shut down with the card installed, but recycles as though you had selected "Restart".
Oh, hardware question. I don't know... have you googled? It sounds like a copout, but Google has the answer to nearly everything...
USB pulls power, XGI ... how big a power supply do you have in this box? And what other expansion cards do you have? And what m/b are you using?