I have an app/icon on one of the homescreens, which is a bit darker, doesn't work, and iTunes report that it can't be synced (the .ipa file is on disk, though, but the app was installed in the previous iPhone's "incarnation" via AppCake). It shows the usual X mark (for app removal) on tap&hold, along with the dialog box when you tap the X, but the app won't be deleted. I also tried hard reset, nothing changed.
What else can I do to clean this up? I won't be needing the app anymore, though.