Network drive cannot be found on a Mac

Greetings,

We have someone using a Macintosh with Mac OSX Lion 10.5.2 and we made an upgrade on our servers and the name was changed.

He does have access to the new share but every time he logs on, he receives a message that the network path (pointing to the old server) cannot be found.

I tried the solution proposed on that site : https://discussions.apple.com/thread/2412372?start=0&tstart=0  with no luck.

The thing that gets me puzzle though is that path: Library/Preferences/loginwindow.plist  does not contain the loginwindows.plist file the forum is referring to. I made a research of the file with only the name login or plist and i have results but actually not the file i'm looking for (loginwindow.plist).

I also went to system preferences -> user and group -> slected his username (he have administrative rights) and then went on items tab. The old server is there but the  -  sign to remove it is grayed out.

Other options was to disable file sharing but no luck with that solution either. In the finder, i have disconnected the server but it still cannot be removed from the system preference even after a reboot.

Any suggestions ?

Thanks