Can't log in gnome session after changing display

[Tom H]

>>>>> Problem: cant' log in the gnome session after changing display
>>>>> resolution to 1280x768, although I still can log in the gnome
>>>>> session by typing 'startx' after booting up Ubnutu as the
>>>>> recovery mode (text command mode?).

>>>> In console mode
>>>> sudo /etc/init.d/gdm  //or kdm
>>>> sudo dpkg-reconfigure xserver-xorg
>>>> sudo /etc/init.d/gdm start  //or kdm

>>> It didn't fix my problem.
>>> After running the first commands, I got the following error message.
>>> "The script you are attempting to make has been converted to an Upstart
>>> job,
>>> but //or is not supported for Upstart jobs."

>> You have to use upstart commands:
>> sudo start gdm
>> or
>> sudo initctl start gdm
>> or
>> sudo service gdm start

> When I typed the commands you suggested, I see the following messages.
> Job is already running: gdm.
> I still see the same error message.
> "The script you are attempting to make has been converted to an Upstart
> job, but //or is not supported for Upstart jobs."

Not having read your initial email, I have just looked at the archives
to see what it was about. At least 99% of my time with Linux is spent
on X-less boxes so I am an X newbie; I was just pointing out the
correct upstart way to start a job...

So, IIUC, you have changed your resolution and can no longer get to
the gdm login dialog box but can get to Gnome by booting in recovery
mode and running startx.

"I Am Me" has suggested that you disable the splash screen by changing
scripts in /etc/grub.d.

An easier way would be to change
#GRUB_TERMINAL=console
to
GRUB_TERMINAL=console
in
/etc/default/grub
run
update-grub
and reboot