Can you click on the cluster group your trying to move and see what node it has set in here to move to...lets say you have CL1 and CL2 and now CL1 is on CL2

can you click on CL1 and see if the parameter is set for CL2 (i cannot remember exact names in the cluster her doing from memory).

Also look for the cluster.log i believe this is on the windows systems and see what the errors are saying.

Failing this you could take offline completely then bring back online.