An exception of type Microsoft.SharePoint.Upgrade.SPUpgradeException was
thrown. Additional exception information: Action 12.0.1.0 of
Microsoft.SharePoint.Portal.Upgrade.FarmSequence failed.

Microsoft.SharePoint.Upgrade.SPUpgradeException: Action 12.0.1.0 of
Microsoft.SharePoint.Portal.Upgrade.FarmSequence failed. --->
System.ArgumentException: xxx@... is an invalid or loopback address.
Specify a valid server address.

I am having Sharepoint Server 2003 with service pack 2.0

I am having MOSS 2007 with 32 and 64 bit.

Approach is In-Place approach.

Any body giving suggestion for this i will appreciate you.