15 char max domain name - Fails to join domain

Hello,

In order to join as a domain member, I enter as …

Domain Name -  a23456789012.com   *NOTE-(16 character long including the dot/period com).

Domain Netbios Name - a23456789012

IP, Admin account and Pwd are all correctly entered.

I’am unable to join domain.

Getting ERRORs like … Failed to join domain!

[KNITT_ERROR: ‘Clock skew too great’]

[KINIT_ERROR: ‘Preauthentication failed’]

[NET_ERROR: Join ADS failed]

Also tried :

a123456789012 in Domain name.

a123456789012\administrator in administrator field

Am I entering wrongly into the boxes ??

My computer is a domain client and i am logged in as a domain user.

Windows 2003 Domain controller with DNS, Exchange.

WD Sharespace is on a static IP and properly connected.

Domain Controller system properties> Comuter Name shows …

     Full computer name: ccc-cc-ccccc.a123456789012.com

     Domain: a123456789012.com

DNS snap-in shows ccc-cc-ccccc

Where am I going wrong ? Any help is appreciated.

Thanks