FYI, the on-board controller for the 8K7A+ is a Highpoint one, not a Promise.
Did you install the AGP Miniport drivers from AMD, or just nothing at all? I was thinking of installing it after SP2, but it might not be necessary...
I'm gonna be putting together a similar setup in a few days when all my components have arrived. Then I'll be in the same fun boat as you.
EDIT: A-duh! You said 8KTA3, not 8K7A. Disregard my irrelevent comments!