I have conclusively traced this down. It starts happening as soon as the automounter times out (typically 10 minutes of inactivity) and unmounts my home directory (accessed over NFS v3). I have no idea what changed in 8.04 to cause this symptom, as I've been using an NFS home directory for over ten years with perhaps a dozen or more Linux distributions and NEVER saw it.
The remote directory is exported using "no_root_squash", which means that root processes can (and do) trigger the mounter and are able to apply their expected permssions on the far end. I can only suspect that the xorg folks changed something or tightened something up with regard to how the X server accesses ~/.Xauthority. Whenever this occurs, all I have to do is go to an xterm (or the console if none is open) and do 'ls'. That triggers the mount again and X permission work correctly - until the next time. Very annoying and I hope it's corrected soon. -- Warning: Unable to open display ':0' and cannot connect to X server :0 https://bugs.launchpad.net/bugs/250712 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs