No VGA display after catalyst drivers installed

Hi all, I successfully built a gaming pc after posting the first build forum, but now I've got issues. I posted this in ATI's Graphics forum as well so I'll word it a little different here and shorten it. Any advice would be appreciated, as always.
System specs:

AMD Phenom II X3 720 2.8 GHz Black Edition

ASUS M4A78T-E Socket AM3 motherboard with an HD Radeon 3300 IGP and DDR3 Sideport memory

Sapphire HD Radeon 4850 512 KB DDR3

Antec 900 case

Antec Earthwatts 650W PSU

4 Gb (2 x 2 Gb) Patriot 1333MHz DDR3

Windows Vista Home Basic 32-bit

A few days ago while playing Doom 3 (yes I finally have a rig that can play games such as this) when the dreaded ATIKMDAG.SYS BSOD happened to me. I'm not sure how many here are familiar with this but I'm going to assume that quite a few have heard of it. Regardless, I didn't get any notification that my system recovered from it, just a game and screen crash and a forced reboot. Ever since then I couldn't get my screen to show anything past the initial windows loading screen until today. I did attempt to have Vista do a system repair but that didn't find anything.

The computer POSTs and I can get into the BIOS and can also boot into safe mode to uninstall both the 3300 and 4850 and load the basic Windows VGA drivers. Hence, both display adapters are both recognized (naturally since the monitor displays something in the case of the 3300).

I finally got the drivers to successfully install for the HD 3300, including the latest version of Catalyst Control Center. However, when I tried to repeat this for the 4850, once again no VGA display and I have to once again boot up into safe mode, uninstall the devices, and start over. The only way I managed the first part was to manually shut down Windows and boot up again rather than let Windows reboot on its own.

I have the onboard display adapter as the default in the BIOS, the latest catalyst drivers installed now (CCC 9.6 from ati's website, not sure what driver # those are) but I did have the drivers previously installed that came with my motherboard and 4850. I tried installing those again to no avail for either card. What gets me is why the drivers worked for the 3300 but not the 4850 if they are the same ones, and what this whole no-VGA display is. From what I've read for the most part, on ATI's site as well as others, is that people have more problems with DVI inputs not displaying and not VGA.

I haven't run driver sweeper yet or any similar program, but I'm at a loss for words (after my rambling post that is). Should I attempt that, or completely reinstall Vista? My PSU should be adequate for this system, no? My 4850's fan works fine, no LED lights after the computer's initial boot-up, so no indication that is has failed.

:*(