Fixed Internet Explorer Minimising After Post

I have some members having trouble with Internet Explorer following an update from Xenforo 1.2 to 1.4.2. The problem persists in 1.4.3. Only add on is the media gallery.

They say: Since the 'update' every time I hit the post button, IE is minimized and I end up looking at whatever else I have open on the PC.

This does not happen when internet explorer is in full screen, only when it is in a window.

I can't reproduce the issue but it has been reported in various versions:
IE 10.0.22 on windows 8 and IE 8.0.6001 on XP