Comment 15 for bug 138331

>I had the same problem with gutsy and pam_mount. I found that trackerd is neither the only problem (gtk-window-decorator is too) nor the root cause.
>It seems that some processes (trackerd for example) are never even notified of a logout by gdm until after pam_mount tries to do a umount.

Then this is a bug in GDM. It should terminate the processes with SIGTERM before unwinding the PAM stack.

>One possible long-term solution is to manipulate the order of the code in gdm. This seems the cleanest, but it may risk lots of instability and require lots of testing.

It needs to do the logout operations in the exact reverse order as the login ones. Failure to do so asks for problems.