On my 'older' systems that include Centos 5.5 and Fedora 12, vncserver is running on ports 580n where n is defined by userid in the /etc/sysconfig/vncserver
I just spent a bit of time getting it working on my new Centos 6.3 server and found it listening on ports 590n.
When did the change occur?
And guess I should test out where it is on Fedora 17...