I notice a thing really strange and confusing/annoying since 7.3 version.
I'm running 7.3 (64bits) on a linux (Opensuse 13.2), KDE 18.104.22.168)
I use a 'focus follow the mouse' configuration (no need to click in a window to get the focus on it),
I never get any trouble with previous versions, but with 7.3, when I change the focus (example I was working in schematic window, then I need to do something in the board window, so I move the mouse over the Board windows, no click) everything work fine except the zoom with the scroll rotary button of the mouse:
I get the focus, I can select a tool with assigned key, I can even change the zoom with the assigned key ALT + F2 (Window fit) or F2/F3 (window 2 or window 0.5) but the scroll mouse button do strange thing (like try to zoom, but get back to previous zoom).
If I click in the window, the strange zoom behavior disappear, until I click in a other window and came back into the Eagle window (whatever is this other window).
This make the 'focus follow the mouse' very less useful...