Resolve an issue in which the Hyper-V Volume Shadow Copy Service (VSS) does not back up virtual machines properly

956697 Windows Server 2008 Hyper-V VSS writer is not used during a backup job because of corrupted or invalid virtual machine configuration files
http://support.microsoft.com/default.aspx?scid=kb;EN-US;956697
Date: 20-Aug-2008
Binaries fixed: Vmms.exe
Binaries version: 6.0.6001.18125 / 6.0.6001.22247

959978 Error message when you back up a Windows Server 2003-based virtual machine on a Windows Server 2008 Hyper-V-based computer: "GetWriterStatus FAILED for Selected writer [Microsoft Hyper-V VSS Writer], writer is in state [9] [VSS_WS_FAILED_AT_FREEZE]"
http://support.microsoft.com/default.aspx?scid=kb;EN-US;959978