Upgrading Exchange 2010 SP1 to SP2 failed

I was trying to update my exchange server 2010 sp1 to sp2 and got the following error~:

Summary: 16 item(s). 0 succeeded, 1 failed.
Elapsed time: 00:02:16

Organization Preparation
Failed

Error:
The following error was generated when "$error.Clear();
      install-GlobalAddressLists-DomainController $RoleDomainController

" was run: "Active Directory operation failed on Myserver.mylocaldomain.local. The object 'CN=Default Global Address List,CN=All Global Address Lists,CN=Address Lists Container,CN=ABC First Organization,CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=ABC-hx1,DC=local' already exists.".

Active Directory operation failed on Myserver.mylocaldomain.local. The object 'CN=Default Global Address List,CN=All Global Address Lists,CN=Address Lists Container,CN=ABC First Organization,CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=ABC-hx1,DC=local' already exists.

The object exists.
Click here for help... http://technet.microsoft.com/en-US/library/ms.exch.err.default(EXCHG.141).aspx?v=14.2.247.1&e=ms.exch.err.Ex88D115&l=0&cl=cp

Can you please help as this is a live environment and I am a bit worried on how to sort it out