Help with my blinkin' 580ex II, please

Last night I was taking some pictures at the school talent show. I had the flash on the camera pointing up at an angle with the bounce card out.

The whole display started flashing. The flash functioned after that but the flashing continued even after I changed the batteries.

Any idea? Thanks in advance.

the wide diffusion thingy is not pushed in all the way.

The only time this happens to me is when I accidentally leave flipped out or a little bit flipped out the wide ange diffuser screen. I blinks like crazy then for me.

Thanks. I can breathe easy now.