not receiving any display data

[Anthony Minkoff]

I set up a VNC server (using WinVNC) on a Win2K system.  I am able to 
access it from a client on another Win2K system (also WinVNC).

However, when I try to access it from my Mac OS X system, it doesn't 
work.  It connects, and accepts my password, but all I get is a blank 
screen.  (It happens to be a blank screen of exactly the right 
dimensions, FWIW.)  Forcing a screen refresh has no effect.  I have 
tried several VNC clients on the Mac: VNCDimension, VNCThing, vncviewer 
running on XDarwin, and three VNCViewer adaptations for OS X 
(adaptations by Tim Senecal, Robert Kedoin, and Helmut Maierhofer).  All 
six clients give exactly the same behavior (except for the color/pattern 
of the blank screen).

The two Win2K systems are on the same physical LAN; the Mac is connected 
by VPN, and is effectively on the same network.

Any suggestions?