Ever since I got my Speedlite 580ex, I notice that when I take it off the built-in flash no longer works consistently, even in Full Auto mode. This is true even if you hit the button to make the flash pop up. Occasionally, though, it will suddenly start working for reasons I can't begin to guess.
I use the Speedlite whenever I need flash, but the built-in flash is good for my wife or other "green boxers" who don't want to pack a Speedlite. Anyone else have this problem and/or know what to do about it?


