OK, how did you install vncserver??? An rpm file or something else(a tar/gz/bz file)?? Something does not look right, I have the vnc-server rpm package installed (but disabled) and I get;
$ rpm -qa 'vnc*'
vnc-4.1.2-9.fc6
vnc-server-4.1.2-9.fc6
$ locate vncserver
/etc/rc.d/init.d/vncserver
/etc/rc.d/rc0.d/K35vncserver
/etc/rc.d/rc1.d/K35vncserver
/etc/rc.d/rc2.d/K35vncserver
/etc/rc.d/rc3.d/K35vncserver
/etc/rc.d/rc4.d/K35vncserver
/etc/rc.d/rc5.d/K35vncserver
/etc/rc.d/rc6.d/K35vncserver
/etc/sysconfig/vncservers
/usr/bin/vncserver
/usr/bin/x0vncserver
/usr/share/man/man1/vncserver.1.gz
/usr/share/man/man1/x0vncserver.1.gz
$ locate Xvnc
/usr/bin/Xvnc
/usr/share/man/man1/Xvnc.1.gz
Check the /etc/rc.d locations (~/rc3{4,5].d and initd directories ) for any (leftover) vncserver SXX Kxx files (K35vncserver or vncserver for examples). Remove them if need be.
Also block/check/edit/remove the /etc/iptables entry for the the vncsever service, either comment out the example line (below) or edit to REJECT;
Code:
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 5901 -j ACCEPT
Do not forget to restart the iptables service(s) when done;
service iptables restart
service iptables6 restart
.