Using 1.433 of Jenkins, 1.37 of plugin.

Windows 7 32bit master jenkins install. Windows 7 32bit slave jenkins install, launched by manually running JNLP from the slave. Created job in Jenkins which is associated to only run on the slave. The job is configured with a Mercurial repository. If I configure the job to trigger based on SCM changes, I get this in the Mercurial polling log:

Started on Oct 5, 2011 9:26:37 AM
No workspace is available, so can't check for updates.
Done. Took 3 ms
No changes

The job has previously run fine and the workspace exists on the slave. The job is configured to download the repository with a subdirectory called 'source' in the workspace. The Remote FS Root on the slave is set to:

c:\jenkins\jobs

The workspace for the job exists as:

c:\jenkins\jobs\workspace\<job name>\source