Last night my SP3 (Purchased last July, on 8.1 with all current updates) has become unable to change orientation while logged in (exactly what thejoker1993 reported here) The accelerometer sensor is working well enough that when rotated the screen does its little shrink/jiggle/grow exercise every single time, it just returns to the same orientation it had before rotating. It seems to set rotation on every arrival at a login prompt: if I log out it will set to an orientation -sometimes correct, sometimes not. It won't rotate at the login screen (it does shrink like it's trying), but it chooses an orientation every time I log off, and keeps it for the subsequent login. I have checked the bleedingly obvious: Orientation lock from the Charms/Settings, as well as from Screen Resolution dialog. Have tried other User accounts too, and have fully shut down etc several times with and without type cover attached. I've tested quite a bit with and without Type cover, with a different Type cover, and with the Dock. It reliably gets to landscape when booted with Type cover or Dock active - but I cannot use portrait at all without a logout (I would usually fold the cover back to use in portrait) The Sensors are showing as 'happy' in Device Manager - I checked for driver update/rollback, but the drivers seem to have never changed. Also tried running the MS Sensors troubleshooter cited as step 5 here : http://www.microsoft.com/surface/en...roubleshoot-surface-touchscreen-rotation#auto , with no luck. It tries to run then reports that "Scripted Diagnostics Native Host has stopped working. A problem caused the program to stop working correctly. Windows will close the program and notify you if a solution is available." Any suggestions out there, as the next step is refresh/reload, which I'd really rather avoid. I'm grimly suspecting it's hardware, so I'll probably need to reload to prove prior to return. Thanks!