I've got 3 of the original style units and all three suffer from varying degrees of key bounce. My unit that has the F18a installed actually has it the worst. The 100% easy fix is as follows. And pardon me if this has been posted at some point in the past. I took one of my wife's emery boards and cut it lengthwise. This made the width about right to fit between the 2 sets of metal fingers underneath the key. More importantly, the thickness was perfect between the fingers. My main unit probably had 15 or so bad keys. I would insert the emery board ahd move it up and down maybe 10 times. It fully fixed every bouncing key. I went ahead and did this procedure to all the keys as preventative maintenance. Just file (no pun intended) this away and try it next time you have bouncy key problems.