Windows 7 64 bit fails during backup with "A shadow copy could not be created. Please check "VSS" and "SPP" error 0x81000019

I continue to get and error and am unable to run a successful backup on a Windows 7 64 bit machine.  I have been successfully running a back using the same settings for years.  All of a sudden I started getting the follow messages and errors:

I have read over all the forum suggestions and believe I have tried them all including increasing the size of my VSS allocated space.  I have cleaned out all unnecessary files on all drives

Here is the error message after the failed backup attempt:

"A shadow copy could not be created.  Please check "VSS" and "SPP" application event log for more information.
Details: The writer experienced a transient error."

Application log error messages (this is the message I get most of the time):

Log Name:      Application
Source:        Windows Backup
Date:          10/7/2012 6:51:24 PM
Event ID:      4100
Task Category: None
Level:         Error
Keywords:      Classic
User:          N/A
Description:
“Backup did not complete successfully because a shadow copy could not be created. Free up disk space on the drive that you are backing up by deleting unnecessary files and then try again.”

I have made sure VSS and SPP are running during the backup

Current VSS allocated space on C:

Used Shadow Copy Storage space: 1.611 GB (1%)
Allocated Shadow Copy Storage space: 1.897 GB (1%)
Maximum Shadow Copy Storage space: 6 GB (6%)

There are other logs that seem to indicate a problem with rights creating files:

Log Name:      Application

Source:        VSS

Date:          10/7/2012 6:27:34 PM

Event ID:      12289

Task Category: None

Level:         Error

Keywords:      Classic

User:          N/A

Description:

“Volume Shadow Copy Service error: Unexpected error CreateFileW(\\?\Volume{3391f838-a0e4-11df-89e8-20cf301b8cd0},0x80000000,0x00000003,...).  hr = 0x80070005, Access is denied.”

Log Name:      Application

Source:        VSS

Date:          10/7/2012 6:25:57 PM

Event ID:      13

Task Category: None

Level:         Error

Keywords:      Classic

User:          N/A

Description:

“Volume Shadow Copy Service information: The COM Server with CLSID {e579ab5f-1cc4-44b4-bed9-de0991ff0623} and name Coordinator cannot be started. [0x80070005, Access is denied.”

Log Name:      Application

Source:        VSS

Date:          10/7/2012 5:28:36 PM

Event ID:      8224

Task Category: None

Level:         Information

Keywords:      Classic

User:          N/A

Description:

“The VSS service is shutting down due to idle timeout. “