Saving Project causes Unity Game Engine to lose focus. Why?

Using: Unity 4.6.0f3 version

Just recently upgraded from 4.3.x to the version above. I'm happy with it, but I have this quirk which is really bugging me.

Whenever I click "Save scene" or save any changes to my work, the Unity Application itself (working in Windows 8.1) actually loses focus, and the other applications I have open receive the focus. (As if I pressed "Alt-Tab" to get out of Unity and go to another application.) Without fail, any time I save the scene, I have to manually Alt-Tab or click back on the Unity application to bring it up again. (Note that it doesn't close, but only loses the focus.)

I'll admit this is minor, but having to save my work every 10 minutes or so, makes me a bit annoyed.

Note that it doesn't happen when using "Save Project".

Can anyone give me some insight on whether this is a bug or something I have setup which is causing this?

Thanks!