When polling I get this error in the log. It repeats for a couple of days now. I don't which of my projects gives this, but it polls every half an hour and gives this NPE.

May 1, 2012 4:00:46 PM hudson.triggers.SCMTrigger$Runner runPolling
SEVERE: Failed to record SCM polling
java.lang.NullPointerException
at hudson.plugins.mercurial.MercurialSCM.compareRemoteRevisionWith(MercurialSCM.java:241)
at hudson.scm.SCM._compareRemoteRevisionWith(SCM.java:356)
at hudson.scm.SCM.poll(SCM.java:373)
at hudson.model.AbstractProject.poll(AbstractProject.java:1323)
at hudson.triggers.SCMTrigger$Runner.runPolling(SCMTrigger.java:420)
at hudson.triggers.SCMTrigger$Runner.run(SCMTrigger.java:449)
at hudson.util.SequentialExecutionQueue$QueueEntry.run(SequentialExecutionQueue.java:118)
at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)