No idea, but try rendering to a new window instead of main window. Could be a glitch about updating the view. In the new window (set to match the main or to a larger size) there is no problem of updating.

Another thing: when the rendering starts you should see in the render control window the progress of 'rendering shadow map' for as many times as many lights with 'depth map shadow' option you have. If that's not happening, and the rendering starts immediately (almost) then you can cancel the rendering and try again.

Sorry, maybe a dumb reply, but worth a try...
Oh and set the minimum displacement bounds to something like 0.5 (0 could give some problems i assume) or uncheck it if you are not using displacement maps in the materials. Message edited on: 09/07/2004 18:31