Sure would like to see if Mac users are having the same problem with Poser as we who are PC users.

My VUE5  will do the same thing once in a while (simply close).  I believe its not Poser specific.  What I THINK and I repeat THINK is happening is that the 512KB reserved housekeeping portion of Ram fills up and the CPU has a "heart attack" (layman's term).  The folks that advise save, save, save, IMHO, are so correct.  One other thing to do is shutdown the computer periodically for at least 10 seconds to flush the garbage out of RAM and that 512KB reserved area.

I think that  MS wonderfully sets aside,  512K for housekeeping (regardless of what or how much RAM you have be it 128, 512, 1024, 2048 MB or a googleplex or RAM).  If it doesn't flush out, you get these neat little surprises.  On the other hand Mac uses as much of your total RAM as it needs, that why the opening question. 

Plutom