Bug 281715

Version:           4.7.1 (using KDE 4.7.1) 
OS:                Linux

after the recent update of KDE:/Distro:/Factory (openSUSE repos), enabling any desktop effects leads to a black screen. no effect in particular seems to be the culprit, and changing from OpenGL to XRender, or disabling "OpenGL 2 Shaders" doesn't help either.

using NVIDIA GeForce 7900 GS with the proprietary driver 280.13, and xorg-x11 ver. 7.6-187.7 from openSUSE X11:XOrg repo.

i have seen similar reports (opensuse forums & mailing list) from users with older NVIDIA drivers, and using nueveau reportedly gives the same result: black screen.

nothing seems to crash, applications start & receive focus, but remain invisible. everything works ok after disabling desktop effects with ALT+SHIFT+F12.

observation: enabling effects via keyboard shortcut turns the desktop & KDE applications black, but non-KDE apps. like opera and FBReader remain visible and operational.

Reproducible: Always

Steps to Reproduce:
enable desktop effects

Actual Results:  
black screen

Expected Results:  
visible plasma-desktop with desktop effects