vnc fails on port 5811

[Barry Yu]

I setup the vncserver as below and vnc remote client can connect 
sucessfully;
vncserver  : 99 -depth 16 -geometry 1000x650
vncserver  : 10 -depth 16 -geometry 1000x650
vncserver  : 12 -depth 16 -geometry 1000x650

But when I use the port 5800 like below and the remote client just won't 
connect ;
vncserver  : 11 -depth 16 -geometry 1000x650
(Port numbers below 11 and above are working ok  except this lucky 11 I 
just happen to find out)

I also noticed that during bootup in verbose mode, everything scrolling 
up with the green OK except the
last line that scrolling in a flash  that  I could only see  it  was in 
red  at the  usual green OK  column, too quick
me to look at what exactly what the message, how do I read it again?
Thanks