Just cracked 3 billion in H10, and the score did not register.  Openfeint did not submit anything, and going back to the level select screen still shows my old score of 1.8 billion.  Looking at the high scores on Openfeint, 3 billion would put me #1 in the world, however, *no one* has scores over 2.2 billion (the negative cutoff point) so I suspect that no ones scores have been saving for this level, perhaps some strange aspect of fixing the negative-rollover glitch.