We did some pretty significant work on the system last night which requires upgrades to all of the desktop versions of Trillian. For those of you who haven't upgraded and are having login issues... Here are the links to the various versions of Trillian
4.2 -> http://www.ceruleanstudios.com/trillian-v184.108.40.206.exe
5.1 -> http://www.trillian.im/get/windows/
5.2 -> http://www.trillian.im/get/windows/beta/
Mac -> http://www.trillian.im/get/mac/
This update shouldn't have any effect on the mobile versions of Trillian.
If you're having trouble getting Trillian to connect after an update, try this:
Windows users: Click the Trillian icon at the top of your contact list, then Manage Accounts, click the Astra connection and Settings, then change the port from 3158 to 443.