Error building Player: KeyNotFoundException: The given key was not present

So, my old cellphone broke (a motorola defy), and I was short on money, so I bought a motorola razr d1

While I was using “build and run” in my old mobile it was working, but with this does not work. I get the following message

Error building Player: KeyNotFoundException: The given key was not present in the dictionary

Very strange, given the fact that it worked in my other mobile, but not in this one. I’ve already activated that 2 developers options in the mobile, installed its adb drivers, so the mobile serial shows at “adb devices” in the DOS.
I’ve also created an keystore, activated / deactivated development build in unity settings, dbut none of these seems to work.

A detail, this only happens in Build and Run. When I build and send the .apk manually to the mobile, everything works.

What can I do? Some sugestions? I’m kind of desperate Thanks.

Have you updated to Unity 4.2.1?
Android: Fixed an issue where a KeyNotFoundException was thrown when trying to deploy to the android emulator.
http://unity3d.com/unity/whats-new/unity-4.2.1