On my mythbox, after upgrading from 12.04 to 14.04, I have an issue turning the TV off-then on. After doing so, I get no output to the screen. I have to manually ssh in and do a "restart lightdm" to get the image back.
I am using an intel i3 sandybridge with integrated graphics.
Anyone else seeing this? I wonder if I need to somehow turn off automatic display detection or something. I saw a setting to this effect in the xfce4-display setting menu, but it didn't help.