[MaddogK]

Your video card appears more than capable to run SHIV, I run it with an nvidia 6600, but I'm not the least bit familiar with those dual core processors. Are all your motherboard drivers installed ? Did you run dxdiag to see if there are any directx issues ? have you tried putting the game graphics into it's lowest detail settings ? Did you try setting the video driver settings to a lower detail setting ?

There's so many possibilities, you must start from the basics.

Another possibility-The Ati HD 4850 may not be fully DX9 compatable.