New user can see all but 1 of them in the List.
If I understand it this correctly, 'new user' can see all other buddies except one. And all the other users can see this buddy.
Lets call the new user "userX" and the one they cannot see "userY" and lets call your ichat server "jabber.myserver.com"
The configuration files for users buddylist is stored in the spool di rectorywhich you can find at /var/jabber/spool/. In there you will find a directory the matches the name of your ichat server. For me that is jabber.clayford.com. In this directory you will find one xml file for eash user of ichat server. Their file name is the OD logon name for the server.
Stop the ichat server service and make back up of any files you edit before you start.
Open the file for "userX.xml" In this file you will see some xml code that starts <item jid='userY@jabber.myserver.com' subscription='xxxxxx'>. there will be a number of them, one for each buddy.
Mke sure the xxxxxx is the word 'both' [with the quotes] and if the text ask='subscribe' exists in that line before the >,remove it. So that definition should now be: <item jid='userY@jabber.myserver.com' subscription='both'>.
Save the file and now open the file userY.xml and check that the item <item jid='userX@jabber.myserver.com' subscription='both'> exists.
Restart the ichat server and the problem should be fixed...