I confirme that it's the poulsbo 3d driver which produce this bug, I install it and start to have this freeze. Uninstall it solves the problem but you don't have the 3d support.
-- [GMA-500] Xorg spontaneously freezes (under heavy loads?) after a while https://bugs.launchpad.net/bugs/393290 You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-psb in ubuntu. _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp