Since VSS-Plugin version 1.9 my incremental build doesn't work anymore. I have a job that is triggered by SCM update. Even if there's no change in VSS repository, I get the following message:
[poll] No previous build, so forcing an initial build.
There are previous builds.

I think the bug is caused by this code in compareRemoteRevisionWith():

//If this is the build then it deserves a build.
AbstractBuild<?, ?> lastBuild = (AbstractBuild<?,?>)project.getLastBuild();
if(lastBuild == null)

{ tl.getLogger().println("[poll] Last Build : #" + lastBuild.getNumber()); }

else

{ // If we've never built before, well, gotta build! tl.getLogger().println("[poll] No previous build, so forcing an initial build."); return PollingResult.BUILD_NOW; }

The logic of the "if" statement should be the other way round; when lastBuild is null, one couldn't call getNumber() without an exception.