Version: unspecified (using Devel)
First of all: I'm not sure whether this is really a KDE problem. It could also be a general problem with X or specifically with TwinView (which only NVIDIA could fix). If this can't be fixed in KDE, please let me know and close this as INVALID.
The problem is that when an application exists full screen mode, the screen isn't redrawn properly and ugly artifacts appear (such as parts of the full screen window still being drawn over the whole screen, gray bars over the plasma panels etc.).
This happens with every application. It happens with Gwenview, it happens with VLC. It even happens with Kwin's full screen mode.
This issue only appears when both my screens are activated (TwinView). It does not appear when using a single-monitor setup.
Steps to Reproduce:
Toggle between normal and full screen mode in an application of your choice.
You can also use Kwin's full screen feature (assign a keyboard shortcut to it).
When exiting full screen, artifacts appear on the screen. I have to minimize a window or switch the virtual desktop etc. to redraw the screen.
Note: if you use Kwin's full screen feature and can't reproduce it, retry several times. In Kwin it doesn't happen each time, but often enough.
Screen should be redrawn properly.
are you using desktop effects? If yes do you suspend desktop effects for fullscreen windows?
Yes, indeed. "Suspend desktop effects for fullscreen windows" is checked. When I turn it off, the problem seems to be gone until I turn it on again.
Anyway, no setting should cause such problems. :-)
*** This bug has been marked as a duplicate of bug 177495 ***