We have prepared an updated version for 3.1.1 version which has most critical bug fixes integrated from our main development branch (Calcutta/4.0).
If you already use Calcutta EAP build, you cannot try this one. Only users of TeamCity versions 3.1.1 and earlier can try the buid.
The full list of fixed issues is available in our issue tracker.
There is also a little post on the release candidate in the dev blog]]>.
Download the build (#6874) at http://www.jetbrains.net/confluence/display/TW/Download+Stable
Do not forget to backup your TeamCity data before upgrading. You can find the instructions at http://www.jetbrains.net/confluence/display/TCD3/TeamCityDataBackup
Please try this release so that if any critical issues are found, we can address them before the 3.1.2 release.
The JetBrains TeamCity Team