GUI editor heeeelp!

So, after a bit of poking around, i finally managed to add my own menu to the starter.fps example. However, one problem that I've had and cannot seem to figure out is how to get the bitmap button to actually use the bitmap I specify in the "bitmap" field. The chunked control works fine, but for some reason the buttons do not. Anyone know how to get my bitmaps showing as buttons? Any help would be greatly appreciated.

Thanks!