Comment 25 for bug 1308105

I am having the same problem. I upgraded frm Mythbuntu 12.04 to 14.04 with the Asus M3N78 motherboard (Nvidia 8200 graphics card & nvidia-304-updates driver).

Using xfce4-settings from Ubuntu 13.10 (as per post #18) fixed it for me. I have not tried using the suggestion from post #10.

There is another fix in this thread that I'll try later this week ->