Not so long ago Ive purchased a used Belkin Card out there on ebay but seems that I made a mistake. It keeps disconnecting over and over. Tried in another system, on another computer, the problem remains. Is it a hardware failure or some compatibility issue (Ive tried it in WinXP only).
It is very hard to tell, but I think your card is broken. If it acts the same on both machines, it must be a hardware problem. However, its also possible that you have a compatibility issue, especially if your hardware is of older date try running it on some Windows 2000 based machine, if possible.