Why won't my DVI connection show boot screen?

I have a Sapphire ATI Radeon HD 2900 Pro Video Card running on a ASUS P5K3/P5K Deluxe wifi motherboard and a Acer AL1916W LCD Monitor. I have an issue where my Video will not display off of the DVI connection when my computer boots. They sent a DVI to VGA adapter and i can use the adpater with the vga cable on my monitor and the boot screen displays correctly. I can switch to a DVI cable once in windows xp pro and the monitor can then display through the DVI cable. I have downloaded the latest video drivers but have no effect on the issue. I have also download the latest BIOS update from asus but am unfamiliar with how to get the .rom update to update the BIOS driver or if i even need to update my BIOS. Any information on why the DVI cable will not come up on the loading screens will be appreciated. If you need any further information please let me know. Thanks :)