The problem is that you've only created an event sheet for 'Soundboard'. So when that layout is showing, its event sheet can tell it what to do. But when you go to 'about', there is no event sheet, so nothing to tell the program what to do?
You should add an 'about' event sheet, and link it to the 'about' layout. Then you can copy/paste your events there, so that the program knows what to do when it's on that layout!