I updated from QB 2.1.33 to QB 3.1.2, after this update automatic builds are no longer triggered automatically when changes are committed. In the system log I see the folowing message:

2010-11-19 11:31:20,149 [Thread-704] INFO com.pmease.quickbuild.DefaultBuildEngine - Evaluating build condition of configuration 'root/Products/Teletrax/BroadCastMonitoringPlatform/Codeline/2/Nightly'...
2010-11-19 11:31:20,274 [Thread-704] WARN com.pmease.quickbuild.repositorysupport.Repository - Repository 'DefaultRepository' in build '2010-11-19_07.57.44' does not have revision set.
2010-11-19 11:31:20,274 [Thread-704] WARN com.pmease.quickbuild.repositorysupport.Repository - Can not calculate change sets as revision of repository 'DefaultRepository' is not set for base build '2010-11-19_07.57.44'.
2010-11-19 11:31:20,305 [Thread-704] INFO com.pmease.quickbuild.DefaultBuildEngine - Build condition not satisfied for configuration 'root/Products/Teletrax/BroadCastMonitoringPlatform/Codeline/2/Nightly'. New build won't be generated.

but this doesn't ring a bell for me what I need to do to overcome this problem