Why do I just get a grey desktop in my Unix VNC Server?

You should run the vncserver script to start a VNC server, rather than the 
Xvnc program directly. vncserver runs Xvnc with appropriate options and 
starts some X applications to be displayed in the VNC desktop. The 
applications it tries to start are specified in $HOME/.vnc/xstartup, which 
can be tailored to your requirements. The default setup is to run the 
'twm' window manager and a single 'xterm' window. If these applications 
fail to run, then you will see a grey 'rootweave' desktop. The most likely 
reason applications fail to run is that they are not in your path. Any 
error messages from this startup should appear in 
$HOME/.vnc/host:display#.log. For further information see the vncserver 
manual page: http://www.realvnc.com/products/free/4.1/man/vncserver.html


Mike