In my app I'm using the following command :
Settings.System.putInt(getContentResolver(), Settings.System.USER_ROTATION, m_lockedInOrientation)
As mentioned in the Android site this will set the default orientation when android can't find one. :
Default screen rotation when no other policy applies. When ACCELEROMETER_ROTATION is zero and no on-screen Activity expresses a preference, this rotation value will be used.
Currently this is the only reason why my app is not working on Android 2.X but only 3.X+ ..
Does anyone aware of a way to workaround it ?