Shabuz LAMP

I use ubuntu at home, few days ago found a weird problem with permission, i was getting popup during login and was frustrated with this. I was going to reinstall my favourite OS(fedora). But later decided against it and found few ways to recover Ubuntu

Permission problem /etc/sudoers ?

start your computer in recovery mode.
(at boot press Esc for the grub menu and select: Ubuntu, kernel …….-c (recovery mode))

sudo chmod 0440 /etc/sudoers
sudo reboot

su must be setuid root to operate
you must issue the following command as root:
chmod 4755 /bin/su

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Re: $HOME/.dmrc file is being ignored

Change permission of user directory and .dmrc file as well as chown those.

sudo chmod 644 /home/shabuz/.dmrc
sudo chown shabuz /home/shabuz/.dmrc
sudo chmod -R 700 /home/shabuz
sudo chown -R shabuz /home/shabuz

you can set 755, 766 and 777 as well.

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Problem with GUI ? Stuck at the login screen??

If you don’t have access to your graphical (GUI) desktop to delete these folders in Nautilus or you’re stuck at the login screen, drop to a terminal by hitting CTRL + ALT + F1, login to your account, and run this command:

rm -rf .gnome .gnome2 .gconf .gconfd .metacity

UPDATE (2008.01.30): Keep in mind that this will only reset your Gnome-specific settings. If you are having problems with your video card, display, x-server, etc., this WILL NOT fix your problems.

Hope this will help

References:
http://ubuntuforums.org/
http://linuxfud.wordpress.com/2007/02/14/how-to-reset-ubuntugnome-settings-to-defaults-without-re-installing/