Got new system, q6600 ( core 2 quad 2.4 ghz) and an asus p2k motherboard.

It came with a 9800gtx, which worked oob.

However, I get GUI lag, I drag a widget, and the ripples stutter.
The whole GUI lags...

Using smbios of macpro3,1. Have tried 4,1 and 5,1 but I KP on tymce kext.

Used nawcom mod cd to install then multibeast to update to 10.6.8.

Vanilla kernel.

I installed lion on another hard drive, and there's no stutter.

What gives?