Managed to remedy my key fob issues (wasn't locking/unlocking doors, trunk etc despite adequate battery) with a good cleaning of contacts with alcohol swab.
Mine recently started acting up on me. It was repeatedly locking the car, even when I wasn't pushing the buttons. Figured it was crud, but took it apart and found this: The little metal buttons had fallen off the rubber piece. Probably making connection when they weren't supposed to. I cleaned it up and glued them back to the rubber with some super glue. Here's what it's supposed to look like: So far, so good.
Since then, I found you can buy replacement rubber pads on eBay for $7.99. Haven't tried one yet, but if this fob acts up again, I will try that. I figure that's easier then having to buy the whole fob and going through the hassle of reprogramming.