My SP4 has been far more trouble than any other machine I've ever owned (including a 1973 VW Bug that leaked oil and had rusted floor boards). Now I am down to (what I hope is) my last gripe... But this will soon be the most expensive thing gathering dust in my closet, if I can't resolve this. The button on my pen - the button you click for 1N, screenshots, and "Cortana" - frequently does nothing at all. All other inputs (keyboard, touchscreen) still work. The "right-click" button still works just fine. I can still write, click, and erase with the pen; when I hover it over the screen, the screen responds. This has been happening since I unboxed the SP five weeks ago. It appears to be sporadic. I chiefly notice the problem when I come out of sleep, but I don't know for certain there's any correlation there (that's when I think to check). There are times it comes out of sleep and it's fine, and times when it's not. If I reboot, it's OK. If I re-map the BT, it's OK. Until it's not OK. Pen drivers appear to be up-to-date. I would appreciate any and all help or suggestions! (When I first took it back to a MSFT store (two weeks after purchase), I was told to create a new user and delete the old one. So I've essentially set this machine up twice. If I have to do it a third time, it will likely be on a Mac.) Other posters I've seen, it appears the pen is always not working, so a replacement pen or mapping the pen is in order. I believe this is a different issue.