Well, I exchanged a previous flawed keyboard for a new keyboard, which has a kind of flaw of it's own. The C and D sliders are smooth at the bottom, but when they are slid towards the top, they get more and more difficult to move. The D slider in particular requires a lot of force to move it to and from the top...like you have to grab it with two fingers and pry it down using muscles in the process. How should I go about dealing with this problem? Jimmy the plate beneath (without opening the case...love that warranty) to loosen the sliders, or return the board for a new one. This board also appears to be making more static noise than the previous one's I've used when I move the sliders or when I change patches while playing.