Webots' problems on Linux..

Webots well works on both Windows and Linux systems. Some days ago I made a mistake, changing screen card driver to NVidia, but my screen card was from Intel.

So Webots's simulation view, the 3D screen, did not work properly. When pressed stop or smt. the program quits. So as usual I tried to redownload and install the Webots. Off course, it did not solve the problem, because it was not the problem.

I also see some flash videos does not work, some works but. Whatever.
So I tried the

sudo nvidia-glx-config disable

command. This command told me that, my configuration is different, namely changed. So I made what did the command tell and changed the config. I also remove all the nvidia related packages from my system. Then, I restart the computer.

Oh my god. I am in console, and getting failures about gdm. I thougt the error is about my removed packages. So I reinstall

linux-386
linux-restricted-modules..2.6....
linux-restricted-modules-386

Then I go to

/etc/X11

and get the old config back. Thanx the backups..

cp /etc/X11/xorg.conf~ /etc/X11/xorg.conf

then

startx

yes! I came back. I think the error was all about the config file.

Because I have been removed all nvidia related packages, when retried the webots!! Yes Webots is also back..

It may be a quite little chance to get the same kind of error, however if it happened, I wish this writing to help you..
I did not search the web about this error, but you may find a better reference, and if so let me know by writing comments..