As an afterthought to this topic:  Would it be a bad idea to automatically set everything to positive when I'm modeling Something in which I'll be using negative properties in order to avoid this situation?  I only ask because I wouldn't want to bind up too much memory or anything else to make Bryce sluggish.  My 'puter is slow enough...

Thanks again, all!

The most exciting phrase to hear in science, the one that heralds new discoveries, is not 'Eureka!' (I found it!) but 'That's funny ...'
Isaac Asimov (1920 - 1992)