I am new to android, now am working with Google maps v2, I have used tabhost to show Google map v2, In this tabhost i need to show two Google maps v2 on different tab. When
I had the same problem (google maps v2 showed only a grey grid in a tab, but if I load it as a main activity without tabs than it works).
Then I added mMapFragment.onResume() and now it works in a tab! Try this:
mMapFragment = ((MapFragment) getFragmentManager().findFragmentById(R.id.map));
mMapFragment.onResume(); // needed to get the map to display immediately
I've found the solution here: https://stackoverflow.com/a/16960527/185493