Took off my shattered original back panel and noticed a difference in the clip configuration on the top side opposite the camera.

The camera side also has a different shape but can be worked into the phone. However, the other side won't allow the panel to do the easy slide or even fit onto the phone. I had to completely remove the little clip with a knife.

That works, but i am not sure how secure it is now and while removing the clip it was impossible not to mess up the black coating on the metal bar inside the panel.

Is my phone unique or is this universal iphone4 back panel not made correctly?