Re: Unable to install linux after insertion of xfx gts 250 512 mb
It certainly sounds like a hardware problem, but odd that it works stable in windows.
Do you have another machine you can try the card in with a livecd? Maybe a friend's machine?
I believe xfx has lifetime free replacement warranty (at least they do on my 8600gt), and they will replace it without argument if you give them a good reason why you think it is bad.
I know it is a pain in the ass to be without for a few weeks while you wait for a replacement, but if there is something wrong with the card, this might be a good way to find out.