NPE when running changelog

Hello,

I have the following error when I try to update an existing project with Continuum. The first checkout of the project works fine, but when I modify some sources in VSS, I get this error. Forcing the build a second time works fine, so it's not a showstopper bug.

org.apache.maven.continuum.scm.ContinuumScmException: Error while update sources.
at org.apache.maven.continuum.scm.DefaultContinuumScm.updateProject(DefaultContinuumScm.java:272)
at org.apache.maven.continuum.core.action.UpdateWorkingDirectoryFromScmContinuumAction.execute(UpdateWorkingDirectoryFromScmContinuumAction.java:58)
at org.apache.maven.continuum.buildcontroller.DefaultBuildController.build(DefaultBuildController.java:166)
at org.apache.maven.continuum.buildcontroller.BuildProjectTaskExecutor.executeTask(BuildProjectTaskExecutor.java:47)
at org.codehaus.plexus.taskqueue.execution.ThreadedTaskQueueExecutor$ExecutorRunnable.run(ThreadedTaskQueueExecutor.java:103)
at java.lang.Thread.run(Thread.java:534)
Caused by: org.apache.maven.scm.ScmException: Exception while executing SCM command.
at org.apache.maven.scm.command.AbstractCommand.execute(AbstractCommand.java:59)
at org.apache.maven.scm.provider.vss.VssScmProvider.update(VssScmProvider.java:209)
at org.apache.maven.scm.provider.AbstractScmProvider.update(AbstractScmProvider.java:386)
at org.apache.maven.scm.provider.AbstractScmProvider.update(AbstractScmProvider.java:363)
at org.apache.maven.continuum.scm.DefaultContinuumScm.updateProject(DefaultContinuumScm.java:242)
... 5 more
Caused by: java.lang.NullPointerException
at java.util.Calendar.setTime(Calendar.java:902)
at java.text.SimpleDateFormat.format(SimpleDateFormat.java:782)
at java.text.SimpleDateFormat.format(SimpleDateFormat.java:775)
at java.text.DateFormat.format(DateFormat.java:314)
at org.apache.maven.scm.provider.vss.commands.changelog.VssHistoryCommand.buildCmdLine(VssHistoryCommand.java:114)
at org.apache.maven.scm.provider.vss.commands.changelog.VssHistoryCommand.executeChangeLogCommand(VssHistoryCommand.java:52)
at org.apache.maven.scm.command.changelog.AbstractChangeLogCommand.executeCommand(AbstractChangeLogCommand.java:91)
at org.apache.maven.scm.command.update.AbstractUpdateCommand.executeCommand(AbstractUpdateCommand.java:63)
at org.apache.maven.scm.command.AbstractCommand.execute(AbstractCommand.java:55)