Can anybody tell me whether it is possible (and easy) to maintain a working copy of Poser 4 on your computer (I'm on a Mac) after upgrading to 5? I like both P4 and P5 for different reasons, and in the event that I have problems with P5 on my Mac, I want to retain access to everything I've done in P4. I would keep all my models and props in the P4 directory, and build everything afresh in P5. Is this doable?