I'n trying to render a fair sized scene, and for some reason the rendering of the Shadow map stops half way, then the program freezes.  Any ideas

HELP

Are you sure the program is frozen?  Sometimes it just seems that way because
Poser isn't communicating with Windows.  But if you leave it alone for an hour or
two it re-establishes it's link.  You are going to get that with a large, complex
scene.
A thought I have is you might want to try to reduce your bucket size.
It will take longer to render the scene, but the communication time
with WIndows will be shorter so it won't seem to be locked up as long.

If you're doing a large scene with lots of shadows then it's best to do it in 2 passes.

Do your colour image first with shadows "unchecked" then save as a png or tiff [I prefer png]

Then render again but this time "check" your shadoes and also check "shadows only"

This will render only the shadows, nothing else so all you'll see is a white image with black where the shadows are. save as a png or tiff.

Take both images into photoshop or whatever you use and put them together as layers.

Select your shadow layer and make it "multiply", this will give you your full image as if you'd done it in poser complete, flatten your layers and save as a jpg, job done!

thx fr the tip on shadows, fixer. i do hope they fix this in P7, as it may be a reason why we still see renders in the gallery here with poor shadows.

thanks for the feed back all, I'll try the smaller bucket sizes :)