Latest VSS hotfix -- 949391
When Volume Shadow Copy Service (VSS) tries to delete hardware support snapshots on a computer that is running Windows Server 2003 or an x64 version of Windows XP, the operation may fail:
http://support.microsoft.com/default.aspx?scid=kb;EN-US;949391
...and I requested the hotfix via email
Read the complete post at http://msmvps.com/blogs/bradley/archive/2008/05/23/latest-vss-hotfix-949391.aspx