iOS SDK: pngs don't show up in interface builder

I've tried adding images to my XCode project. I've droppe开发者_高级运维d and dragged a couple of pngs into my project, and they are listed in the left pane.

When I open up a XIB in Interface Builder, the images don't show up in the media library.

Any ideas? Thanks.

I had a corrupted Xcode 4 install. Thanks to those who contributed answers!

While adding the images to your project make sure that you tick the check box for Copy items into destination group's folder (if needed)

Also try the PengOne's solution.