Quote - Poser 8 itself doesn't crash at all. So I'd assume Firefly would be able to address 16GB of RAM as a 64-bit application? And if not, rendering in 4 different processes would then make each process able to address 4GB?

Poser Pro's renderer is 64 bit, not Poser 8's. You Poser cannot render in 4 different processes, just in 1 with multiple threads, so that won't help you.

So, are you using a 64bit OS or not (probably not). And is your problem really memory related, did you check the taskmanager?