FWIW...the service releases MUST be installed with Poser 5. They aren't optional. I think if you installed the service releases, you'd find P5 not only much more stable, but much faster. There was a thread last week, where someone was having trouble with P5 being so slow it was practically unusable. Turned out they only had the first two service releases installed. When they installed SR3, Poser 5 ran more than three times faster (as measured by rendering the same scene under both setups).