C[omp]ute

From: andrew cooke <andrew@...>

Date: Tue, 23 Feb 2010 09:37:17 -0300

This is a strange bug that just started happening on my KDE desktop -
it may be related to either the "zoom out and show all windows"
feature, or Firefox 3.5.7, or something else entirely (the first time
I saw it I had Windows 7 running in Virtual Box, but the second time
was soon after a reboot without VB running).

The symptom is that (1) minimizing windows appears to have no lasting
effect (windows "shrink" and then "reappear") and (2) it is not
possible to change virtual desktops.

In fact windows do, in a sense, minimize - what reappears is just an
"image" of the window.  If you "unminimize" from the task manager you
can then use the window again.  More generally, the bug is related to
rendering getting confused.

To fix this, open System Settings, select Desktop, then the Advanced
tab, and change compositing type from OpenGL to XRender.  Click Apply.
 This should fix things, but will be slow.  You can then change back
to OpenGL and it will be quick again (and work correctly).

Alternatively, rebooting fixes things.

Andrew