Hi Damocles,
Brilliant! At first I didn't think that your solution would be of any help, but the idea of keeping the bounding box above the level geometry solved the problem of getting stuck.
Here's a screen capture of where my new bounding box is positioned:

@jcl: My problem is solved! I'm still curious as to why the c_move didn't work, but I'm moving on. Feel free to ignore my bug submission if you don't have time to work on it.