Starting on December 11, 2009, customers who use Office 2003 will be unable to open Office 2003 documents that are protected with the Active Directory Rights Management Service (AD RMS) or with Rights Management Services (RMS). Customers will also be unable to save Office 2003 documents that are protected with AD RMS/RMS.
Users may receive the following error message when they try to open AD RMS-protected or RMS-protected documents by using Office 2003:
"Unexpected error occurred. Please try again later or contact your system administrator"
This symptom affects Office 2003 products that are used together with AD RMS/RMS. This includes Word 2003, Excel 2003, PowerPoint 2003, and Outlook 2003. This does not affect the 2007 Microsoft Office system.
The expiry date for the license information within the definition file that is used by Office 2003 to enable IRM functionality is set to December 10, 2009. This problem occurs because the expiry date was not renewed.
To work around this problem, open the document by using the 2007 Microsoft Office system.
or get the update here