How can I set non-60Hz-Modes?

[Dexter Filmore <Dexter.Filmore@gmx.de>]

I used to do that with the nvidia tool on nv, but now I'm a little stuck:
No matter what I do X comes up at 60 Hz. I need to do 50 tho so the attached 
plasma tv doubles it to 100 (at 60 it flickers, plus pulldown problems)

EDID reports a refresh range of 58-62 Hertz which I overrode in xorg.conf.  
When I feed it a custom mode with xrandr --newmode / --addmode it does 50hz 
alright, but I can't make it permanent from xorg.conf.

I tried the Preferred Mode option and "ModeValidation" tho I am not sure the 
latter is nvidia specific.

X log can be found at:
http://www.vaultofsages.de/~dexterf/xorg60hzlog

xorg.conf below.

Can someone have a look and advise, please?

Dex


Section "ServerLayout"
    Identifier     "Layout0"
    Screen      0  "Screen0" 0 0
    InputDevice    "Keyboard0" "CoreKeyboard"
    InputDevice    "Mouse0" "CorePointer"
    Option         "Xinerama" "0"
EndSection

Section "Files"
EndSection

Section "InputDevice"

    # generated from default
    Identifier     "Mouse0"
    Driver         "mouse"
    Option         "Protocol" "auto"
    Option         "Device" "/dev/psaux"
    Option         "Emulate3Buttons" "no"
    Option         "ZAxisMapping" "4 5"
EndSection

Section "InputDevice"

    # generated from default
    Identifier     "Keyboard0"
    Driver         "kbd"
EndSection

Section "Monitor"
    Identifier     "Monitor0"
    VendorName     "Unknown"
    ModelName      "LG Electronics LG TV"
    HorizSync       28.0 - 83.0
    VertRefresh     24.0 - 62.0
    Option         "DPMS"
    Modeline "1920x1080_50"  141.50  1920 2032 2232 2544  1080 1083 1088 
1114 -hsync +vsync
    Modeline "1920x1080_24"   63.00  1920 1976 2160 2400  1080 1083 1088 
1098 -hsync +vsync
    Option       "PreferredMode" "1920x1080_50"
    Option "ModeValidation" "DFP-0: AllowNon60HzDFPModes"
EndSection

Section "Device"
    Identifier     "Device0"
    Driver         "intel"
    VendorName     "intel corp"
    BoardName      "SandyBridge"
EndSection

Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    Option         "TwinView" "0"
    Option         "DynamicTwinView" "0"
    Option         "FlatPanelProperties" "Scaling = Native"
    SubSection     "Display"
        Depth       24
    EndSubSection

EndSection



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