In /etc/sysconfig/displaymanger
add -xorgAc to DISPLAYMANAGER_XGL_OPTS
e.g.
DISPLAYMANAGER_XGL_OPTS="-xorgAc -accel glx

buffer -accel xv"
Run:
SuSEconfig
as root
reboot or restart the whole X thing...
Run steam on DISPLAY=:93
I use CrossOver... so mine would be something like:
DISPLAY=:93 /localhome/ccox/.cxoffice/win2k/desktopdata/cxmenu/Desktop/Steam
There's too much in most 3D games to prevent them from running under Xgl. This technique bypasses Xgl and runs them on the Xorg server that is behind the scenes. You can use this for other things, like ut2004 and googleearth (for example).