VNC4 accepts connection 5900 but refuses 5901

[Frank Hamersley]

I am no doubt missing something blindingly obvious, but...

I have installed the v4 release and can successfully connect to the session
on 5900.  However I can't connect on 5901 - instead I get the "10061
connection refused" message!

If I shift the base port number to 5910 I can connect to :10 but still can't
connect to :11.  Can anyone illuminate me on this as I had expected any
number of sessions to be enabled by default?

I wanted to deploy VNC to share management of a server between 2 people.  I
wanted the first person to always connect on 5900 and the second always to
connect on 5901.  That way I was planning to avoid a collision if both
should connect at the same time (because we will be using ssh tunneling on
those preassigned ports).

Regards,
Frank.