Microsoft has posted an update on the Download Center for those of you using Word 2003.
This update is a further update to changes that were made back in January of this year after a December 2009 court ruling directed changes to the XML tagging implementation in certain Microsoft Office products.
This is an update to Microsoft Office Word 2003. You must install this update if you have been instructed to do so in a separate communication from Microsoft. Office 2003 Service Pack 3 is a prerequisite for this update.
This update will affect a particular custom XML tagging implementation. For technical details on the affected custom XML tagging functionality, please see KB978951.