Resolution fixed at 640x480 on ACER 5742G and nvidia-current

Question

I installed Ubuntu and installed nvidia driver with generating nvidia X11 config.

As a result I have 640x480 resolution. No matter what I specify (I specified 1366x768 resolution) in xorg.conf.

~$ xrandr
Screen 0: minimum 320 x 200, current 640 x 480, maximum 8192 x 8192
LVDS1 connected 640x480+0+0 (normal left inverted right x axis y axis) 344mm x 193mm
   640x480        59.9* 
VGA1 disconnected (normal left inverted right x axis y axis)
HDMI1 disconnected (normal left inverted right x axis y axis)
DP1 disconnected (normal left inverted right x axis y axis)

Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    SubSection     "Display"
        Depth       24
        Modes   "1366x768"
    EndSubSection
EndSection

How can I get the resolution as I specify?