tigervnc-1.0.1_p20100529 has a memory leak, as long as the follow patch is not included. Xvnc will consume very much memory over time. http://atkac.fedorapeople.org/tigervnc11-rh597172.patch I've installed this 1 line (!) patch and now, no memory problems over the last 3 days.
A new version was stabilized