On 2015-03-30 13:08:11, Alfredo Palhares wrote: > Any ideas how can I debug this problem further ? Have a look at X's logfile, /var/log/Xorg.log. There should be messages that say the modes are being removed, and why (not enough Vram, some parameter out of range, etc.). It's likely warning or errors, so it should be among the output of egrep '\([WE]{2}\)' Xorg.0.log. Good luck, -Martin