I run Arch Linux with a "normal" Xorg desktop, that is, using LightDM as login manager and the i3 Window Manager (with some components from Xfce, GNOME and KDE as needed). The graphics is the integrated Intel graphics from my i7-4770T processor.
Since some time ago, it happens that whenever I press Alt+Left or Alt+Right or any of the Alt+F1..F10 key combinations, the screen flickers shortly. The action I wanted to do (e.g. go back in the browser history) is executed, but the screen flickers.
I have a suspicion that the kernel key bindings for changing the VT are executed, i.e. the VT changes, Xorg is notified and will display on the new VT.
I have tried adding
Option "DontVTSwitch" "true"
Option "XKbOptions" "srvrkeys:none"
xorg.conf in the appropriate places, and I can see them being accepted, but neither changes the describes behaviour.