Small IR bug on gamepad

So, I'm having a bit of a problem, specifically (although it might carry over to other games, haven't tested) with Animal Crossing: City Folk, namely that no matter what stick I bind the IR to, it doesn't hold still. As in, I can use the stick to move the in-game curser around to click things, but then it 'resets' and returns to the middle of the screen as soon as I let go.

Any suggestions on what to do?