The upgrade to 10.1.3 also included OpenSSH 3.0.2p1.
I found out that there is a change in how authentication with other servers is handled in this version. When I connect to one of my OpenBSD boxen, I get asked for my S/key password before I have a chance to enter my normal password. That's of course very unfortunate if you have not set up your s/key passwords, or do not carry them with you.
The fix was for me to add one line to the /etc/ssh_config file:
PreferredAuthentications publickey,password,[Shown on two lines; enter as one]
keyboard-interactive
Mac OS X Hints
http://hints.macworld.com/article.php?story=20020226012735776