Hi
If it serves as any help, I get these messages in syslog as soon as the error occurs:
console-kit-daemon[885]: console-kit-daemon[885]: GLib-CRITICAL: Source ID 49 was not found when attempting to remove it
console-kit-daemon[885]: GLib-CRITICAL: Source ID 49 was not found when attempting to remove it
console-kit-daemon[885]: console-kit-daemon[885]: GLib-CRITICAL: Source ID 58 was not found when attempting to remove it
console-kit-daemon[885]: GLib-CRITICAL: Source ID 58 was not found when attempting to remove it