After the installation from update manager, and every time I boot up my machine, I get a error with three options out of which I am forced to click OK for “Run Ubuntu in low-graphics mode for just one session” option.

Resolution upon reference from url (http://ubuntuforums.org/archive/index.php/t-1242813.html) for Ubuntu 9.10:

Take a backup and edit xorg.conf file:

sudo cp /etc/X11/xorg.conf /etc/X11/xorg.conf_bkp
sudo gedit /etc/X11/xorg.conf

Delete this Section Device:

Section “Device”
Identifier     “Device0″
Driver         “nvidia”
VendorName     “NVIDIA Corporation”
BoardName      “GeForce 8400M GS”
EndSection

And Edit the Section Screen as:

Section “Screen”
Identifier     “Screen0″
Device         “Device0″
Monitor        “Monitor0″
DefaultDepth    24
SubSection     “Display”
Depth       24
Modes “1440×990″
EndSubSection
EndSection

Here we go, no more low graphics mode issues.