I have a late 2006 BlackBook (2,1 model) for which the trackpad has become worn. By this I mean it's really smooth and shiny from years of use. This has made it less responsive to finger movement compared to the "roughness" it originally was. Anyone have any thoughts on how to improve its responsiveness? Anyone replaced one? If so how much did it cost and was it an easy DIY? It's not a huge issue but thought I'd check and see what options are available.