Comment 17 for bug 1308105

^No AMD owns ATI, the other major graphics card provider.

I am also experiencing this problem on integrated Intel graphics on Xubuntu 14.04 when using HDMI. It's the first distro I have used on this system but I never had the problem on Xubuntu 12.04 on my previous sytem (which was VGA/D-sub).

I do not get 'NULL' in my /var/log/Xorg.0.log but the issue is basically the same problem. I do get null in dmesg however:

[code][ 0.152426] ACPI: SSDT (null) 0004C4 (v01 PmRef Cpu0Ist 00003000 INTL 20061109)
[ 0.153472] ACPI: SSDT (null) 000433 (v01 PmRef Cpu0Cst 00003001 INTL 20061109)
[ 0.160066] ACPI: SSDT (null) 00015F (v01 PmRef ApIst 00003000 INTL 20061109)
[ 0.163743] ACPI: SSDT (null) 00008D (v01 PmRef ApCst 00003000 INTL 20061109)[/code]