I just did a security patch upgrade on an Ubuntu Karmic server. I know, Lucid is out but I'm not ready to jump on that bandwagon with any more servers yet.

Immediately after the upgrade, I noticed that SSH logins took literally forever and were followed by:

timeout in locking authority file: .Xauthority

It turns out that something with this latest upgrade caused my home directory to not be writable by... me. This was definitely not a problem before the upgrade. I'm assuming it will only affect those using encrypted home directories.

Quick fix: after logging in as myself, I did:

sudo chmod u+w /home/[yourdirectory]

It didn't have to be done recursively because all of the subdirectories had retained their permissions.