It's not the mouse. I am having the same issue. I'm using 8.1 on surface pro with wedge mouse + wedge keyboard. Usually, about every 6 hours, the BT stops completely, then the wifi connection goes down and when clicking on the wifi network icon, it
says "no connections available".
I've also found that when using the network, i.e. sync'ing to skydrive, the BT mouse becomes extremely laggy to the point of non-use where I have to wait for whatever application is using the network to stop.
This is absolutely a bug in the MARVEL chipset or drivers. This also seems like something very basic that should have been found months ago by MSFT DEV/QA.
Is there any solution? (And no, BLD 9477 does not resolve this issue either). I work remotely most of the time and this is my primary PC, I would hate to switch back to Mac or some other brand of laptop.
~kenny