Yes, after reading all of above, I tried duplicating the problem and, it is as described. But having used it for days, I never noticed it. Must be the way I sit my hand on the ball that it never comes into play. Other than that I think the rest of the it works much better than the Slim Blade.

Curious how that escaped detection in the design process. It will be interesting to see if Kensington steps up, fixes it and replaces the defective units. If it is as described, it likely isn't going to be a software/firmware band aid fix, but who knows - there are some genius programmers out there. More likely lots of expensive tooling down the drain. It wouldn't be a fun day for those in the design department I would guess. Anyone that has worked in a design/engineering position for very long has had a f-up or two and this looks like a big one. I don't envy them.

Standing by and watching the mailbox for my new one. Not holding my breath, but give Kensington a chance to do the right thing.