Same behavior in my laptop after update to 11.04. Apparently a segmentation fault in X server.
[ 16727.462] 15: /lib/i386-linux-gnu/libc.so.6 (__libc_start_main+0xe7) [0x12ce37] [ 16727.463] 16: /usr/bin/X (0x8048000+0x1a411) [0x8062411] [ 16727.463] Segmentation fault at address 0xa3d8440 [ 16727.488] Caught signal 11 (Segmentation fault). Server aborting [ 16727.496] Please consult the The X.Org Foundation support at http://wiki.x.org for help. [ 16727.496] Please also check the log file at "/var/log/Xorg.0.log" for additional information. [ 16727.496] ** Attachment added: "Xorg.0.log.old" https://bugs.launchpad.net/ubuntu/+source/gnome-session/+bug/760695/+attachment/2101792/+files/Xorg.0.log.old -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/760695 Title: Ubuntu suddenly logs-out -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs