I'm not sure if Poser 5 is to blame for the memory management problems. In the case of Windows OS, it's probably the OS to blame, based on reports I hear, although I admit the first release of P5 Windows was a slap-dash job of out-sourcing and a wretched bug-fest. But in the case of OS X (Jaguar, Panther), memory management has some serious flaws, one of which is called "page-outs", a hereditary disease it got from Unix, a 30-year-old OS. Things can get so bad due to excessive page-outs that the only cure is to shut down and restart. Of course, this is in a system which the OS X geeks will try to tell you should never be shut down, except for security updates.