As we share the computer with other members of my family, we use this wonderfull feature "open a new session" when a session is locked.
But on my new computer (Acer Aspire with ATI GPU running openSuse 11), using this feature crash X

When I run
gdmflexiserver --xnest
(new session in a window), this is working fine

But when I want a new session in full screen (i.e. new display), this is causing my X to crash

Does anyone already met this problem ?
Do you have some workaround/solution ?

Thanks for your help,