I took eight photos in HDR on my iPhone 4. I brought them into iPhoto and they looked normal until I cropped them. Then they showed three off-set images superimposed on top of each other.

Greetings,

I took an HDR + Normal picture on my iPhone 4 and then cropped both images in iPhoto. Only the edits show up, no other extra copies. That suggests there is something going on with the data on your iPhone.

Try:

1. Force iPhoto to close: http://support.apple.com/kb/HT4211
2. Turn the iOS device off and on: http://support.apple.com/kb/HT1430

Test iPhoto with a fresh picture.

If the same issue occurs:

1. Share your edited images to your computer for safe keeping: http://help.apple.com/iphoto/iphone/1.0/#blnkbe43137b
2. Backup your iPhone: http://support.apple.com/kb/HT1414
3. Delete iPhoto and and re-download it.

Test iPhoto with a fresh picture.

If the same issue occurs:

1. Import all camera content from your iOS device to your computer and then delete all camera content from the device (cleaning out your camera roll): http://support.apple.com/kb/HT4083
2. Turn the iOS device off and on: http://support.apple.com/kb/HT1430

Test iPhoto with a fresh picture.

If the same issue occurs:

Restore your iPhone: http://support.apple.com/kb/HT1414

Hope that helps!

Haven't experienced this on my iPhone 4 yet. What does it look like? Got a screenshot?