My Fusebox application upgrade experience

I'm doing an integration and upgrade on a Fusebox application which has passed through at least 2 other developers, both of whom I know. There are a few things in the code which look 'wrong' to me but they work. My rule is, if it works, don't rewrite it unless you need to.
As I go along, I'll be noting some of these things and either commenting on them or rewriting them. There are also a few things in Fusebox itself that I'm not so happy with, but as I haven't had a hand in it's development since it was created, any comment I make will fall under either gripes or future enhancements to the framework.