Freezing session problem with Compiz

I’m having a frozen session with compiz on OpenSuse 11.1.
2gb memory, AMD X2 6000, nvidia 8600 GT, nvidia driver

Using the single row 4 column wall in Compiz, it freezes whenever it shrinks to show all workspaces. If I pick a workspace within 5 seconds there’s no problem but more than 5-10 seconds and the session locks. I have to telnet/ssh into OpenSuse 11.1 from another PC and Kill the compiz process to get the session back.

IIRC, its a similar problem with the cube but its been a long time since I tried the cube.

The compiz settings are the defaults except for the wall.
Device options in xorg.conf
AddARGBGLXVisuals = True

with/without these options the problem occurs
XaaNoScanlineImageWriteRect = true
XaaNoScanlineCPUToScreenColorExpandFill = true

Any help is appreciated.