Why won't iPhoto find/import photos from iPhone4?

Gawd... this used to work reasonably well but not perfect, and now its just frustrating. Sync'd my iPhone to my iMac just fine, but now I wan to download the 75-100 pictures I took today at a car show. Nothing shows up when I try to use iPhoto. Why is this? There are a million posts for this and dozens of suggestions that may be wild goos chases. This is Apple software not recognizing Apple hardware... something that should NOT happen. This should be so easy my grandson could do it.

All I can tell you is that it works for me. The only time iPhoto doesn't see my iPhone 4's pictures is when I take them in Camera+ (a third-party app) instead of the Camera (and I could fix that in prefs if I wasn't so lazy).

So you plug your iPhone 4 in and open iPhoto ... what exactly does happen?