Plot hole: Although it is explained how the chipmunks were able to get away with the balloon race by tricking Ms. Miller, wouldn't Ms. Miller know that the chipettes were in on the balloon race? Especially considering the fact that she is their guardian? Also, why would she offer to babysit the chipmunks if she has chipettes to look after herself? Despite this, the chipettes were never brought along to Dave's house with Ms. Miller. And what is Ms. Miller still doing in Dave's house if she thinks the chipmunks are with Dave? Unless maybe she's taking care of the house...