Only HDMI is connected.
xrandr says :
I've no doubt that this TV can handle 1920x1080 'cause PS3 users play blueray @1080p on it (even if Sony says rez is limited to 1360x768).
Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 1920 x 1920
VGA_1 disconnected (normal left inverted right x axis y axis)
_OutputNumber: 1 (0x00000001)
ConnectorNumber: 1 (0x00000001)
DVI-D_1 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 1600mm x 900mm
_HDMI: 1 (0x00000001) range: (0,1)
_Coherent: 0 (0x00000000) range: (0,1)
_Backlight: 8645728 (0x0083ec60) range: (0,255)
_OutputNumber: 2 (0x00000002)
ConnectorNumber: 2 (0x00000002)
1920x1080 60.0 *+
1280x1024 59.9 60.0
800x600 60.3 56.2
640x480 60.0 59.9
By the way, I'm unable to have more than 800x600, so 1360x768 is far far away
Still trying ...
Any way, this is to be a HDTV related problem, not driver one.
Or something is wrong between PC and HDTV ... Who said "You !" ?
Note : NVidia users are able to display 1080p by deactivating some validation modes, but it's another story.