As explained in this bug report : https://bugs.launchpad.net/xorg-server/+bug/889459
I have a tablet, I installed Ubuntu on it. Live CD works great, but when installed, when I boot : black screen. If I plug an external display, the two displays work great, and if I unpplug the external one, the original one still works great. Next boot : same problem. I tried to launch a script at session stratup with xrandr --output LVDS1 --mode 1024x600 --rate 75 (a working config if I manually inject it) but it stills don't work. I tried with nomodeset (http://ubuntuforums.org/showthread.php?t=1613132) not useful. Do you have any ideas on how to be able to use the tablet without having to plug an external device first ?
Thanks a lot !