Try this and tell me if it works.  Move the client node to a different TSM
Policy Domain and then move it back into the one it was in.  Then you will
have to set up the schedule again.  Then stop and start the scheduler
service.

I know you are asking yourself, what kind of a crazy thing to do. Well...
read on if you want to know why?

A while back we had to change from 1 configuration manager server to
another.  One of the things that we had been managing was our policy
domains.  Well, when you break the subscription you also change the status
of the domain from managed to not managed.  At this point you can
resubscribe to the new server an managed that same policy domain if nodes
are defined to it.  So in order to managed the domain again we had to move
our nodes to a different domain (STANDARD) and then back.  This of course
deletes all the schedule associations.  Well, after we went through this
process our nightly backups all went pending (we were in prompted mode).
After a call to support we found that someone all the information about how
to contact a node is kept with in the policy domain that the node is
registered in.  If you remove it then it looses the IP and port to contact
the node on.  So this is why I am guessing that this might work for you.
Again, please let me know if it does.

Kyle
payne AT berbee DOT com