We are unable to remove a particular job from Visual Cron. When attempting to delete a job I get this error in the log.

2/25/2010 3:37:03 PM Err Select case ex: System.Collections.Generic.KeyNotFoundException: The given key was not present in the dictionary.
at System.ThrowHelper.ThrowKeyNotFoundException()
at System.Collections.Generic.Dictionary`2.get_Item(TKey key)
at OBOKIIHBDBPMCFALPGECCIFHCDJPEDKODDGK.GHAMFGCEDFOEIDCMEENNAFIOCECPBDKLJMLG.PEJGOMOCGLLLFFDLGLPJHLCONPOHICELDNDH(TaskStateClass , MessageClass , String )
at OBOKIIHBDBPMCFALPGECCIFHCDJPEDKODDGK.FCAGFFJBIPDCJFIIPJFLJDAMAMIJDMPBDLCI.KAKDJOHMMLDIAKLOEANIFIKOMHPEMDFAJMBC(String , MessageClass , Byte[] )

Solved - simply restarting the Visual Cron services did the trick.