I never used language or theme switching before so I don't know if I would have had problems with older versions or not. It was only when I started using the log ecards feature and tried to delete some old cards that I started having problems. I know this is a Dreamhost problem, NOT a Coppermine problem. But if any dreamhosters hang out here and have fully functioning CPG's at the latest version, I could use your help!
Bah. Compiling PHP locally (and running it as an apache module) fixed everything for me. Cheers.