DV4000 display is in XGA mode does not fill the screen

HP Pavilion DV4000 running in XGA mode (1024x768) with blank bars at the bottom and right side of the screen. It should be WXGA 1280x800.

I posted my problem on Fixya a couple of days ago and haven't received a useful response.

What did you finally determine was the problem? We've reinstalled HP driver CD, Intel Graphics driver, XP SP2 all to no avail. Because you see the smaller image at POST and pre-boot time as well, I'm thinking it's hardware. Would really like to know what you found out that fixed this problem