Broken Pipe Error After Project Rename

[architectpianist]

Hi,
This is truly one of the most dissatisfying errors - after you've written a beautiful program and then you find that changing the name stops the program from even launching. I changed the name in Xcode 4, and it gives me a "write failed: Broken pipe" error every time I build and go (there are no compile errors, however). The iPad shows the default image without loading the app. I didn't change any code. I left Bundle Name and Bundle Identifier alone in the plist, and I changed the Bundle Display Name to the new name. Is there anything I'm missing or anything I've done wrong?
Thank you!

[architectpianist]

Also, I tried to restore to the snapshot of before I renamed the project, but I was appalled to find that Xcode renamed my entire .xcodeproj file, along with all the snapshots that I had taken of the old one! So all in all I had zero snapshots in the Organizer. (It showed up as two projects: OldName.xcodeproj and NewName.xcodeproj)
If anybody could explain this that would be great, because I'm not liking this renaming method at all.

BTW, the app is running perfectly on the sim, it's just broken piping on the iPad.