How can I stop iTunes sync from removing one of my development apps?

I have a half-dozen apps installed on my iPhone via Xcode's Build and Run function, and they've always been unaffected by syncing the phone with iTunes. Now one of the apps has started disappearing from the iPhone every time I sync with iTunes. If I watch the sync progress at the top of the iTunes window, I can see the step where it says "Removing 'Appname'."

If I connect the iPhone and browse its sync settings, on the Apps tab, the app icon is visible on the home screen, but it does not appear in the "Sync Apps" list where I can check which apps to sync. Oddly, if I put the app into a folder, and iTunes removes it, and then I reinstall it from Xcode, it will go back into that same folder.

The only difference I can think of between this app and the others is that this was originally an iPad-only app, and then I changed it to an iPhone/iPad app. The app does work fine on the phone until iTunes removes it. I've 开发者_开发问答confirmed that "iPhone/iPad" is selected for the Targeted Device Family setting for all configurations. I've also tried removing the development provisioning profile from the phone and reinstalling it.

Does anyone know why iTunes would be removing this app even though it leaves the others alone?

Drag and drop app build and provisioning profile into iTunes sync phone and see if issue is persistent. I think its because itunes cannot find your app in its App library.