This hack shouldn't generate too many errors, being as small and simple that it is. Those of you who are recieving them can only be installing the hack incorrectly. (installed correctly, you should get no parse errors/T_Variable warnings) Ofcourse the hack has performance issues for the larger forums (I have a smaller forum, and my pages still generate at .3 seconds).
Anyway, I'm going to see what I can do to fix it..