Microsoft Office 2003 Update Error: 80070643

I am running Vista Ultimate 64-bit, and have been getting error code: 80070643 while updating Microsoft Office 2003 recently (previous updates under Vista worked fine).  The specific updates are:

Security Update for Microsoft Excel 2003 (KB933666)
Security Update for Microsoft Office 2003 (KB934180)
Security Update for Word 2003 (KB934181)
Update for Outlook 2003 Junk Email Filter (KB934708)
Update for PowerPoint 2003 (KB933669)

All other Windows updates work fine.  These updates are not already installed, and the Microsoft Knowledge Base solution (http://support.microsoft.com/?kbid=903774) was ineffective.  Any help here would be greatly appreciated.