UIFileSharingEnabled has no effect

I've added UIFileSharingEnabled to the .plist. Per suggestions, I have:

• removed the app and redeployed it several times
• attempted to disconnect after redeploying

I have not been able to get the app visible in the File Sharing section in iTunes. On another app, this works flawlessly. The app where it doesn't work has a bit exotic internals (an easily portable game; as such, it has its own mainloop, it doesn't have a main nib, ...). The app where it does work is pretty much standard deal. Also, testing was done on two different devices: it worked on iPod Touch 4 with iOS 4.2.1, but it didn't work on iPhone 3GS with iOS 4.2.1.

Since it's a bit difficult to isolate the problem (and I could probably spend several MORE hours isola开发者_JAVA技巧ting it), is there any other known requirement to get file sharing to work?

CFBundleDisplayName is additionally required in the .plist. Why Apple elected to require this, I have no idea.