When I play a video fullscreen in smplayer, I get graphical glitches in a horizontal line about a quarter of the screen from the top, particularly visible if I skip a few seconds, but also when there's a significant change.
I have a fairly recent Nvidia gpu and an LCD monitor. The issue was there in 15.04 and it's still there in 15.10. It does not occur in full screen, nor does it happen with VLC or the default movies app. Any ideas?