VHDMP event ID 3 while running Windows Server Backup (wbadmin)

Hi

I am running Hyper-V on WS2008 R2. I've applied the registry fix for FsDepends.sys as it is suggested in http://support.microsoft.com/kb/2013544 but I'm still getting VHDMP enent ID 3 errors every time when I run wbadmin:

Level Date and Time Source Event ID Task Category
Error 13/03/2010 01:00:53 Microsoft-Windows-VHDMP 3 None Failed to surface VHD \Device\HarddiskVolumeShadowCopy113\VHDS\VM05-###### Hard Disk.vhd. Error status 0xC0000061.
Error 13/03/2010 01:00:41 Microsoft-Windows-VHDMP 3 None Failed to surface VHD \Device\HarddiskVolumeShadowCopy113\VHDS\VM01-###### Hard Disk.vhd. Error status 0xC0000061.
Error 13/03/2010 01:00:32 Microsoft-Windows-VHDMP 3 None Failed to surface VHD \Device\HarddiskVolumeShadowCopy113\VHDS\VM03-###### Hard Disk.vhd. Error status 0xC0000061.

The fix that registers the Hyper-V VSS writer is also applied.

VM01 is WS2008 R2 virtual machine
VM03 is WS2003 R2 SP2 virtual machine
VM05 is WS2003 SP2 virtual machine

The integration services are installed on all VMs.

The VHD drives are located on iSCSI connected Dell MD3000i array.

Does anyone have a clue what those errors mean? 

Thanks.

- Svet