what can cause vista not respond to keyboard input when the rdp session has been locked

[GS]

there is this new install of vista pc with busniess premiere ed.

works but
1. if rdp connect as a domain users and then subsequenlty lock the session,
the console keyboard is ignored even for ctl-alt-del is pressed
2 if a login session left overnight or is the pc left idle overnight, no one
can rdp connect


what can I do to fix the problems above?

 

[GS]

still not sure why but sometimes control alt shift end key would give relief
from non response.
it is not the firewall for sure.