What kind of system specs are you running on Darkworld?

I haven't had any kind of problem like this since I upgraded my hardware...

...previously, running on a Core 2 Duo with a mere 4 GB RAM, I had this sort of thing quite a lot.

That was also at least one service pack ago though too... I'm on SR2.1 at present... till I get home tonight at least...

...but anyway, something I've done in last few months has resolved the issue of UI freezes or crashes, e.g. on trying to cancel out of a render, for me... and Poser seems a lot more stable all round...