Connects but hangs at logon

One of those hard "intermittent" problems where
connecting from home to the office computer the terminal
services connects, but hangs at logon.

If I try to connect again get "The requested .. cannot
complete because the terminal connectior is currently
busy processing a connect operation."

I can then connect using a different logon name and
successfully logon but cannot logout, nor can I reboot
the remote by using RUN->CMD->SHUTDOWN during the second
connection.

Any suggestions?

Thanks