I also have this bug and it happens when switching windows via mouse
click, Alt-Tab, or any of the various Launcher methods. I also have a
Nvidia graphics card 8400GS. I have no idea where to begins figuring out
which package is causing whindows to go white when brought into or out
of focus. I
messed up attachment... here it is.
** Attachment removed: all three screenshots in one
https://bugs.launchpad.net/ubuntu/+bug/990069/+attachment/3114061/+files/screenshots.jpg
** Attachment added: all three screenshots in one
