This same thing has happened to me (...okay to my poser figures). I don't think its a memory issue as I have 1GB of RAM. Interestingly it happens intermittently when I load two M2 characters, even when I use the Millenium Null to ward off cross talk. I'd say it happens maybe 5% of the time when I'm using two figures in Poser, and I've never been able to see a pattern or figure out why. Usually I just treat it as the fluke it seems to be and continue on, although it would be interesting to hear if anyone has figured this out. Matt