Not able to login after changing .xinitrc

I modified the .xinitrc in order to start only the xterm. I created a new .xinitrc, as I didn't have any in my home directory, writing sth like 'which xterm'. After restarting the system I couldn't login to that user. Even if I type the password it takes my back to the login window prompting for the password again.
Booting from a live CD I removed the file .xinitrc from the home directory of that user, but I still have the same problem. Any idea?

Look in the logs for what is failing in X. Check /var/log/Xorg.0.log for lines starting with EE.

(EE) Failed to load module "nvidia" (module does not exist, 0)

I don't have problems with the other user even if they have exacty the same .xinitrc file.