SMS Logon Point Removal?

In SMS 2.0 BDCs are configured automatically to be Logon Points for SMS (to assign Clients to their appropriate site. We have recently removed some old BDCs from our NT4 single domain network. They were removed from SERVER MANAGER as well. But SMSis still trying to update them on a weekly basis and as it can’t find the server it creates an error message. Does anyone know of a way to remove them from SMS?