Just got word from the guy's at Tweakhound that they have found a fix for Delayed Write Errors on ATi's Radeon 9500 Pro with the help of ATI's Terry Makedon & Raymond Skarratt.

I recently purchased a ATI 9500 Pro video card. Upon installation of the card I immediately began getting Delayed Write Errors. I have narrowed down the problem to this section of tweaks.