On the Droid 3, when you move apps to the SD, you actually move them to "media area" as opposed to the external SD card. The entire app is not moved and some of it remains in the 'phone' area.
Now it is well documented, that widgets are not to be moved to the SD Card as they may stop working. If they stop working, moving them back to the 'phone' may not work and the widget will have to be uninstalled, then installed.
I, and many others have reported, that there seems to be an issue when moving apps off of the 'phone' storage and into the 'Media area" or in the case of my OG Droid the SD Card. There are times when the addressing to the app in the 'media area' or SD card gets lost, resulting in the app vanishing. This happens to me during the following scenarios:
- Power off/Power On the Droid/Droid 3
- When On the Droid/Droid 3 attached to the PC/Laptop and I set it for data, then disconnect
There is one constant with these 2 scenarios, the operating system loses contact with the 'media area' or the SD card and it does not restore properly when the either the Droid/Droid 3 or there is a hand off back to the phone after USB disconnect.
Sometimes, a power off/power on will restore one or more, sometimes, it makes it worse.
Just my opinion, most likely your will differ.
Good luck,
Bob