I recently got that error in Poser 4 and I have a pretty beefy system (P4 2.4ghz, 1g RAM). I was rendering to a new 2000 x 1000 window, got the error and decided to save my work and reboot. Once I saved, I could then render to a new window without rebooting. YMMV, but try saving your image first and then rendering. -Nancy.