I have run Poser 7 on my new laptop under Vista Home Premium without many problems.  My new laptop came with a crappy intel video chip--since I didn't know anything about Intel's video chips I didn't think much of it until I installed Poser.  After installing Poser I could not get the Open GL to work and I have the most recent driver for the Intel video chip.  I can, however, run Poser under Screen D and it works fine--the preview just isn't as pretty as what I am used to.  It's really funny, my underpowered old laptop handled Poser's open GL fine, but it was running XP.  It also had ATI Radeon Video Chip, unlike this crappy Intel one.   So I'm not sure if it's an Intel chip problem or a Vista problem.  Daz Studio and Cararra display fine.

I was able to render a complex image with IBLs in Poser wihtout problem, it just took a while.

I wish I hadn't upgraded my desktop to Vista, but my OS took a dump and I figured since I had to reinstall everything anyhow I should use the next, upcoming OS.  I just hope Vista doesn't become another Window's ME.