Yeah, I really do NOT recommend flashing your video card unless you absolutely know what you are doing. Most times this will void your warranty. If you are having an issue with your NEW card, send it back for a new one.
I've flashed my BIOS one time to gain a better OC, but that was on an older card and it wasn't going to kill me if I toasted it. When you start to do that sort of stuff, you need to be prepared to accept the risk involved.