Thank you! :)
You're absolutely right, I take it you're playing on Windows. I developed and tested mostly on OS X, then compiled on Windows at the end and play tested for completeness. I also noticed the resolution resetting, which is a terrible feature, but I didn't care enough to stay up late with work in the morning.
This is my first pygame/fullscreen combination, so I don't know right away how I'll solve this, but I will. Thanks for reminding me about this, I probably would have forgotten!