There was a post in the openSUSE newsweekly mentioning possible problems with compiz in 11.1.
Might help to update to the latest packages and reset your compiz config.. Direct link to CyberOrg for more info :
CyberOrg » Compiz on openSUSE 11.1
After these updates I'm running compiz without any glitches so far... also on 11.1 , GNOME with an Inter 945 GM chipset.
Hope that helps,
Wj