ABR 11 Adv WS: Error "Failed to create the volume snapshot"

I have ABR 11 Advanced Workstation installed on a Windows 7 64-bit system. I am backing up my C: system partition to a D: partition (same physical hard drive). I have been getting the errors shown below.
I found the posting http://forum.acronis.com/forum/24553 but the error codes are different so I thought I would ask. The very last post by Alexander Brajkin says:
This is a known issue and errors won't appear in future product updates in such situations. Meanwhile these messages can be safely ignored - backups are created and can be restored just fine.
Is this true in my situation?
TIA...
Error code: 50247
Module: 16
LineInfo: 14181c22ef45b06d
Fields: $module : C:\Program Files (x86)\Acronis\BackupAndRecovery\DiskBundle.dll
Message: Failed to create the volume snapshot.
--------------------
Error code: 65520
Module: 0
LineInfo: bd28fdbd64edb8bc
Fields: code : 2147942450
Message: The request is not supported
--------------------
6 Information 1/23/2012 4:47:21 PM Locking partition C:...
7 Information 1/23/2012 4:47:21 PM Failed to get VSS metadata for backup.
Additional info:
--------------------
Error code: 704
Module: 64
LineInfo: 26556611c50a732a
Fields: $module : C:\Program Files (x86)\Acronis\BackupAndRecovery\DiskBundle.dll
Message: Failed to get VSS metadata for backup.
--------------------
Error code: 65520
Module: 0
LineInfo: bd28fdbd64edb8bc
Fields: code : 2147942450
Message: The request is not supported