Wow, It's been a while since I posted here, so lets give this a try.
Running Windows 8.1 with my GTX 580.
If I ctrl+alt+del and click switch user (doesn't matter if I switch or not), both my screens will go blank for a second, like it is recognising the card again .This causes (in 90% of cases) my desktop icons, widgets and open windows to move about. Either all to screen 1, or swap, so Chrome is on 2 and everything is on 1. It is very infuriating.
Running latest drivers also. I am unsure if it is Windows doing this, either by design or bug, or if there is an issue with my graphics card, but I have never had a problem with my card before or anywhere else but this.
The same issue can sometimes happen (albeit rarely), if I run a fullscreen game and quit, the transition back to the desktop will sometimes cause this.