Kindle1 Scroll Wheel- The cursor responds erratically

I have a Kindle 1, with the scroll wheel. In "menu", it won't always go to the book I've selected; in "manager" it won't put the cursor on one or more items, such as "move selected item to secure digital card." At Amazon, someone suggested changing the battery. I had a replacement battery and did so, but the problem endures. Is there any hope for K1 maintenance, or must I save up for a newbie?

Do you think the scroll wheel just needs to be cleaned?
Someone on the Amazon kindle discussion boards mentioned Portatronics for repair (http://www.portatronics.com/). I don't know anything about them, so this is not a recommendation, but it might be worth investigating.

Depending on what you paid for for the K1, it might make sense to purchase the K3. I upgraded and really like it, although I honestly do miss the scroll wheel. It is still the most convenient way to move up and down in a book and the menus.

k4k