I'm working on a scene that requires a human figure with deep holes on its chest... I just discovered that's impossible to do this with boolean operators in Bryce... Am I wrong? Is there a way I can get this working?

you have to set the mesh to "solid when boolean rendering" under the menu you get when you click on the little "E" (you need to have the mesh selected)

I had a lot of trouble doing on poser exports. I finally figured it out on one of my images, (and it was more than just clicking on solid), but I can't remember. Lemme go find that file and I'll see if I can figure out what I did...

I made a wound in a figures chest by setting the particular mesh object to solid and clicked positive, and used a negative rock to make the hole. If the figure is clothed you have to do it to the clothes as well. You need to ungroup the poser figure first, and then regroup it once you have it right. Best to do it in a new document and then copy and paste to your scene.

Thanks to all of you, people! I'll try and let you know after defrag!

That's it... all of the individual parts have to be put to positive, then grouped, then the new object put to positive. I had just made the whole group positive without considering the individual parts.