Hi Steven,
No I didn't think that would fix it but just wanted you to know the medium trust config wasn't needed. By configuring it for medium trust you lose NeatUpload and some other things become more difficult.
I'm pretty sure the error you are seeing is a bug and will be reproducable and also easy to fix. Admittedly better testing happens for MS SQL and MySQL since I have sites running on those. So you get to be the guinea pig and tell me the bugs you encounter but rest assured I'll fix them quickly.
I'd fix it right now but hey its friday night ;-)
Cheers,
Joe