So my uncle has a 40D and he's had it since 2 years ago, brand new. this case never happened til i bought him a 430exII. we were playing around with it, and this problem has occurred 3 times with the flash on.
The 40d seems like its frozen. when pressing the shutter button, it doesnt focus. its as if the shutter button is broken. i turn it off and turn it back on; the same issue.. the only way of resetting the problem is pulling the battery out and plugging it back in. its a really strange occurrence. (have not tried it too much without the flash yet)
has anyone had this problem? could it be cause the 430exII is newer technology than the 40d and it causes some kind of improper technological information to the 40d?
help! 
Peter
