I purchased a Gainward 4400 from newegg. The first one was faulty, so I spoke with both newegg and gainward about replacing it. Both would do it, practically no questions asked. The gainward people were actually pretty apologetic, but just said "this is a hard card to make."
In the end, I had gainward replace it. Just put the new one in yesterday and having no problems. It's an unfortunate situation, but at least it was taken care of quickly and to my satisfaction (it took about a week). I think you'll find some of the posts at newegg saying the same thing.
Good luck