Yast2 in TighVNC remote admin session

Installed OpenSUSE 12.1 into a VirtualBox. Chose LAMP software and Gnome desktop. Note ended up with Desktop Kernel and not Default Kernel (not the real issue). Enabled remote administration from Yast2.

When I access this from a VNC session, Yast2 will not start from the program selector. Yast2 though will start if it is chosen from within the VirtualBox manager.

Yast2 does not run, but Yast runs OK from a Gnome terminal. Yast2 will start up from a terminal, but none of the options within it will run.

In var/log or var/log/yast2 it appears that there is nothing written to the logs when choosing Yast2.

Anyone have any ideas why Yast2 will not work from a remote session, but will from the VM host. All other applications seem to run OK from the remote VNC session.