I'm done putting the finishing touches on 1.3.1. You can take a trip on over to our SourceForge Site
[*1] to download a copy. Because of the security fixes, if you are running 1.3 this is a required upgrade. For those interested in the changes that are coming click 'read more'. Security Fixes
Added Who's Online Hack
Many Calendar Bugfixes
Upcoming Events Block Fixes
Help File Support in Blocks
Bugfixes to User Settings Page
I think that is it. This should go a long way to making the 1.3.x tree more stable.