I tried following a tutorial on Android Maps V2 Quick Start But when I run the app, a blank map screen is shown. My phone uses android 2.2.1.
I had the same issue and the solution was to delete the debug.keystore. Then i did an
adb uninstall com.example.myapp
Then clean and run the application again.
I think the problem was due to the fact that i copied and pasted in my manifest a dummy API key and I first deployed the application with it.