So I finally converted Propane::Font over to use vertex buffers instead of immediate mode. The implementation is completely moronic (one giant vertex buffer with absolutely no overlap), but it does the trick for now.

When I was implementing it, I realized that I am an idiot and I was referencing characters 32 units ahead in the ASCII table.
So yeah, there you go. That's your screwed up text of the day.

It's all fixed now, but I don't notice much of a performance improvement.