I'm having the same problem as well.
[userdomains] domain conflict: /var/cpanel/users/maini contains a MAIN domain already owned by damaini at ./updateuserdomains line 184, <F> line 2.
[userdomains] domain conflict: /var/cpanel/users/pcmedic contains a MAIN domain already owned by damaini at ./updateuserdomains line 184, <F> line 2.
[userdomains] domain conflict: /var/cpanel/users/xili contains a MAIN domain already owned by damaini at ./updateuserdomains line 184, <F> line 2.
File: /var/cpanel/damaini.accts
,clientdomain.com,147.202.65.106,damaini,,,,,,,,,damaini,server2.domain.com,x,,512000,,,,damaini_Main,,,,,,,Sun Sep 26 12:25:56 2004,1096219556