Using the new editor in mods

[Michael]

I'm working on converting a mod for 2.1 and the old mod used the editor. Now in 2.2, I get the following error at the top of the page:

IPB WARNING [2] usort() [function.usort]: Invalid comparison function. (Line: 384 of /sources/handlers/han_parse_bbcode.php)

My guess is that I have failed to load a necessary cache. I know that developers docs are coming, but is there any chance on getting some insight as to what I've failed to do in my code? I was using the standard code from here to load up the editor in my code.