Can't log into "locked" server

[Lyndia M. Oudeh]

   Previously  when  I  logged  off  Windows  I locked my Windows session
   runnng  on  my VNC server, which is my work machine.  Then I would log
   in  to  that server from my viewer on my home machine.  Now I can only
   log  in  from  home  if I leave my Windows session on the server up an
   running.   I  want  to  be  able  to  log into my server with a locked
   session.  I  must  have  inadvertently changed some VNC setting, but I
   don't know what I did.  Any suggestions?