Mouse hover doesn't work when Microsoft mouse is connected I'm using the Microsoft Sculpt Ergonomic Desktop for one and a half years now and had no problems with it.

A couple of days ago I noticed weird behaviour with the mouse. The same behaviour was with the trackpad as long as the mouse's dongle was connected to the Mac. 

Any mouse-over/hover behaviour is gone. The Dock doesn't pop up automatically, no tooltips or sub-menus (which only open when hovering the curser above them) show up.

I did do some changes before I noticed it. I created an admin account and set my personal account to standard; I activated the firewall; I activated FileVault. I'm uncertain if this is just a coincidence. 

Additionally, a strange side effect occurs when plugging the dongle in or out: If a web browser is opened, you can see that the web-page's layout slightly shifts horizontally. 

My Mac's specs:
OSX 10.10.3 (14D136)
MacBook Pro (Retina, 15-inch, Mid 2014)

The keyboard/mouse combo: Microsoft Sculpt Ergonomic Desktop

Update

I tried replacing the batteries, which did not help.

I tried out the mouse on my colleagues Mac and it had the same behaviour.

Interestingly, when I turn off the mouse while keeping the dongle plugged in, the track pad behaves normal again.
I know it's an old thread but since there are no solution mentioned for the Microsoft Sculpt Ergonomic Mouse... I had the same problem and fixed it just now. 

It is a hardware issue where the little button below the Windows blue button gets stuck. I had two of these and the one where it was clickable, it worked fine and the second one had the button stuck and the hover over wasn't working.
I stuck a push pin into it and tried to pry it out through the rubber layer on it and it now works fine.

So it was down to poor quality buttons on this nice mouse.