The "Multiple SCMs Polling Log" shows for me (see [1]):
ERROR: Failed to record SCM polling for hudson.model.FreeStyleProject@1c9f55c[mingwGitDevEnv-test-git]
java.lang.ClassCastException: org.jenkinsci.plugins.multiplescms.MultiSCMRevisionState cannot be cast to hudson.plugins.cloneworkspace.CloneWorkspaceSCM$CloneWorkspaceSCMRevisionState
at hudson.plugins.cloneworkspace.CloneWorkspaceSCM.compareRemoteRevisionWith(CloneWorkspaceSCM.java:291)
at hudson.scm.SCM._compareRemoteRevisionWith(SCM.java:356)
at hudson.scm.SCM.poll(SCM.java:373)
at org.jenkinsci.plugins.multiplescms.MultiSCM.compareRemoteRevisionWith(MultiSCM.java:91)
at hudson.scm.SCM._compareRemoteRevisionWith(SCM.java:356)
at hudson.scm.SCM.poll(SCM.java:373)
at hudson.model.AbstractProject.pollWithWorkspace(AbstractProject.java:1549)
at hudson.model.AbstractProject._poll(AbstractProject.java:1521)
at hudson.model.AbstractProject.poll(AbstractProject.java:1455)
at hudson.triggers.SCMTrigger$Runner.runPolling(SCMTrigger.java:439)
at hudson.triggers.SCMTrigger$Runner.run(SCMTrigger.java:468)
at hudson.util.SequentialExecutionQueue$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.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Maybe this (also) is an issue with the Clone Workspace SCM Plug-in?
[1] http://mingwgitdevenv.cloudapp.net/job/mingwGitDevEnv-test-git/scmPollLog/?auto_refresh=false