I am observing an odd bug with my SP3 (or maybe it's also Windows 8.1's fault) in conjunction with my Arc Touch Mouse (Surface Edition): Whenever I bring up the Metro network settings dialog (e.g. to enable/disable WiFi or switch to a different network) and then return to the classic desktop my mouse is "gone" for at least 30 seconds. The mouse pointer disappears and the system does not react to mouse-movements nor -clicks. After a while the mouse-arrow re-appears but still does not respond to mouse movements for a while and only after 30-60 seconds it is finally responding again and one can use the arc Touch as normal. During that time only the pen reacts and can be used to point and click (the touch cover's touchpad is disabled while an external mouse is attached to the SP3). Since in my current location I have to switch WiFi-networks a lot (one to get to the Internet, the other to access the company's intranet) this is getting really quite annoying! A really odd bug that slipped through MS' testing and quality assurance here! M.