gnome windows corrupt upon downward movement

[tehdon]

Binary package hint: xserver-xorg-video-trident

I have a Toshiba Tecra M1 with a Trident Cyberblade XP4-32m video card. I am using the Feisty 7.04 herd 3 alternative install cd for a clean install, then the usual apt-get update && apt-get upgrade. When I change the defaulted driver from vesa to the proper driver Trident in the xorg.conf file, I have window corruption. I can move the windows up, or up and left, or up and right, but the moment I move a window down the whole window turns black, but the rest of the desktop is still fine. The window stays black until I move it off bottom of the screen and then move it up again, then the window corruption disappears and turns normal again. As a temporary work around I have been able to pull the binary xorg driver from the Debian unstable xserver-xorg-video-trident version 1:1.2.3-1. This driver seems to work great with no corruption.
On a separate note, do we know if there is any trident 3d accel?

Thanks
-Donald-