I may be having the same issue on my blue Leo. In my case, it's the A key. If I hit the key off center, toward the bottom, it often sticks with a "crunchy" feel. I blew the switch out with compressed air, but no luck. Upon closer examination, I noticed that if you grasp the key stem and shift it up / down, there is a bit of play and you can reproduce the crunchy feel if you actuate the stem when it does this. The other switches that work fine don't have the side to side play. I contacted EK to see what they say.