AV does a popup- glitches mouse

[Thomas]

Alt-tab is not really supported in fullscreen mode. This is because of a base lib that we work and not really much we can do. A new version was very recently out, but require some rewriting from us. Perhaps we can fix for a future patch or at least future games.

For now, do not alt and tab when in game unless really needed. If you must do it, run in windowed mode.