Seeing your specs in the other topic, and yes your right it would drive me nuts if im in that situation.
I cannot find what else you have tried or i maybe overlooked it.
But may i ask what catagory network cables, like cat5 or cat6 you use? And als what type of monitor cable you use like hdmi 1.4 or 2.0.
Also check your xbox network app and see how the connection is running