Bug#715508: Acknowledgement (gdm3: System settings → displays offers unusable screen resolutions)

[axst at users.sourceforge.net]

Even though the mode lines for the display in /var/log/Xorg.0.log are the same, under
Squeeze GDM offers an additional 16:9 resolution (1364×768). Under Wheezy GDM only offers
the modes detected by X, which are all 4:3.