[tsetse-fly]

I use Carbon Emacs because Cocoa Emacs has a black square in the center of the frame for the visual bell. Also, there's no visual separator between windows when you have your scroll bar/fringes turned off. Aquamacs is too exotic.

[martenveldthuis]

I used to get that up until a few weeks ago too. Try recompiling from the latest head, it's fixed for me.