swap Fx function incorrect after k750 is turned off/on, or intermittently

Created by: corebots

first of all thanks for this tool, very helpful.

on the k750, when the 'swap Fx function' is set, it seems to work fine until i turn the keyboard off/on, then the toggle button in Solaar stays set 'ON' but the Fx keys no longer are switched > pressing F11 toggles full-screen instead of rising the volume. This also seems to happen occasionally without reason, not sure if it has to do with power management or there is another reason. This is particularly stressful on my setup as the Fx-F12 key is set to switch between soundcard outputs. then the above mentioned bug happens, i press F12 and the computer goes to sleep instead of the expected switching of sound output :D

next, when i try to re-enable the 'swap Fx funcion' switch, i run into bug #252 (closed) and need to restart Solaar.