users are not getting imported after updating NetBIOSDomainNamesEnabled as true

hello,

I have imported external users successfully,howevere they have different netbious name in AD

For example :

Netbious NAme - ABC

domainname - mydomain.com

when I run full sync , user's accoutn name was - mydomain\username , while it should be ABC\username

After that I found following URL :

http://iedaddy.com/2012/01/wrong-domain-name-in-accountname-after-user-profile-sync/

I performed below steps :

1. removed existing sync conenction in existing service application

2. DEleted external user profiles who is having mydomain\username account name

3. updated NetBIOSDomainNamesEnabled=1 for existing UPSA

4.Created new sync connection

5. Run Full Sync

NetBIOSDomainNamesEnabled  As a result external users are not at all getting imported.If I chnage the NetBIOSDomainNamesEnabled  as false then I am able to see users but those are with mydomain\username which is not expected.

Would you please let me know what can be the reason behind this issue ? how can I import users with ABC\username ?

Thank you in advance !

Dipti Chhatrapati