Thanks for the info!
Never had this problem with our AE-1, but it's good to know that if we ever did, we'd know the cause!
My husband loves his AE-1, so I will pass this on to him.
BTW... I guess the way I look at it is when you make the camera ready to take a picture (focus, aperture, etc) you should be prepared to 'take the picture'... ie...not having to advance the film first.