Division by zero: It's a form of optimization. You aren't allowed to divide by zero, which mean you need to guard against it in your code.
And unregistering PLAYER_ENTERING_WORLD will probably break more than it fixes, unless you only do it for the xpbar.
Auras: I was talking about the size of the frames that hold your aura icons. Those that are referred to as self.Auras, self.Buffs and/or self.Debuffs. Those are the ones you had to fix the width on.
I suggest you post some code if you want further assistance.
