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.

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

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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.