So, I've got some good news. A Casio technician called me the other day and explained to me my problem with some keys being louder than others. He said this happens when Casio's sit in a store for a long time and not played. They can get dusty inside. My piano, although not played, sat on the floor of the store for a long time before I got it. The problem is very fixable, and he's got no problem driving the 75 miles to my house to do it. Thats very nice that Casio is doing this. It says a lot about the company.