Okay, ran some tests last night.
Galaxy S/Android 2.3.3:
Both my game and the test app detailed above lock with GC errors on resume
Nokia X/Android 4.1.2:
Both my game and the test app resume correctly. However, following a resume, my game is throwing an error on exit in SpriteBatch.Setup (gd == null).
Android 15 & 17 Emulator:
My game failed completely to resume, not even getting the GC errors - I’m guessing that this is due to the size of the game and the amount of content it has, plus the emulator being dog-slow. Test app resumes correctly.
Since the Nokia X has less memory than the Galaxy, I’m guessing that this is specific to older Android versions, but just don’t have the hardware to confirm.