Thank you both. Looks like it's something to do with my Poser install. Strange, though, that I have the same issue with both 7 and Pro. I'll try the partial reinstall trick, and if that doesn't work I'll just try to live with it until Poser 8.

"If I were a shadow, I know I wouldn't like to be half of what I should be."
Mr Otsuka, the old black tomcat in Kafka on the Shore (Haruki Murakami)