Sounds like you have the GPU hanging. Take a look at https://wiki.ubuntu.com/X/Troubleshooting/Freeze for how to obtain a batchbuffer dump that is needed to troubleshoot issues like this.
** Tags added: 965gm freeze karmic -- X3100 intel graphic card + compiz = freeze https://bugs.launchpad.net/bugs/459230 You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-intel 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