periodic "failed to connect" that fixes itself

[McEwen, Art]

I've got VNC 3.3.6 server installed on a home server and most days it works
great.  Every once in a while however I'll get a failed to connect (from
either side of my router/firewall) while my FTP server on the same machine
operates fine.  I have an automated reboot every day at 2AM and if I just
leave things alone the next day VNC is back online again, the day after that
it might not be.
 
Any ideas?
 
Thanks,
 
Art McEwen