Hmm. I've been using Poser all along. Originally, I added Mac OS X onto an existing system, with a pre-existing Poser install. I did install Mac OS X onto a new partition rather than over the existing Mac OS 9 partition, though that "shouldn't" make any difference.

Now I'm using it on a new system that came with Mac OS X. However, I never actually "installed" Poser on it, which may or may not make a difference. I just copied the entire Poser 4 folder tree onto the new system. (I, too, wasn't willing to try to reinstall all the stuff I've accumulated over the years!)

Do you have OTHER Classic applications that are working, or do you perhaps have some more general problem with your Classic setup?