Ran out of disk space and is the syslog and dmesg full of lines like this?
May 18 09:59:12 atlantis kernel: [ 1226.498570] Valid eCryptfs headers not found in file header region or xattr region, inode 2753436 May 18 09:59:12 atlantis kernel: [ 1226.498573] Either the lower file is not in a valid eCryptfs format, or the key could not be retrieved. Plaintext passthrough mode is not enabled; returning -EIO
I noticed this after upgrading my laptop to Ubuntu 12.04 and was looking in the syslog why the Gnome shell crashed when I clicked on the workspace switcher.
Apparently it is a bug that already exists for years, but no real patches or workarounds yet and the commands it contained were not that helful. I finally I found this blog, which pointed me to the culprit, a corrupted empty Skype xml file (~/.Skype/shared.xml).
Coincidentally, that file probably also forced me to log in every time I started Skype, as it couldn’t store my password.
