Hi, I have the same situation as you, send my xfx 4890 to the following problemhttp://i859.photobucket.com/albums/ab154/nadimac24series/IMG00155-20100919-0311.jpghttp://i859.photobucket.com/albums/ab154/nadimac24series/IMG00152-20100919-0310.jpg
As you can see I can not even get into windows, they told me it was: Graphical corruption in the boot or POST on your system, in my case did not have to send me a new 4890, they told me I had three options.
Wait a month for a XFX 4890 XXX (mine is standard) or 5830 and sent to me once, I was told to add 60 Dollars for 5850.
I have not yet responded. ) = At the moment I have no money for 5850