Also
its weird.. even when there is nothing being executed my machines stay in the claimed state odd....
The dedicated scheduler that the MPI and parallel universe uses, holds on to claims for up to UNUSED_CLAIM_TIMEOUT seconds, in an attempt to reuse those claims should another job come in. The default value for UNUSED_CLAIM_TIMEOUT is 600 seconds, so after 10 minutes, you should see the claims go away.
-greg