Question : WMI and SqlServerWriter under VSS writers both have issues, why do they always fail?

We have an XP Pro Sp3 machine having some occasional VSS errors.  We thought this was fixed before, but it still occurs.  It usually occurs after something has accssed VSS (NTBackup, Carbonite, etc).  Nothing is accessing it at the same time.  After VSS is used, immediatly after the status of both the wmi writer and sqlserverwrtier goes to status 5 "waiting for completion" and then a short time after, it's status reads 7 "failed" and stays this way until the next system restart.

This is verified by doing a "vssadmin list writers" from the command prompt.  

We also occasionally get the following in the windows application log (every day or two):

Event ID 8193:
Volume Shadow Copy Service error: Unexpected error calling routine CoCreateInstance.  hr = 0x80080005."

Can anyone help shed some light on this?  The Carbonite or NTBackup backups do not fail, but the error is something we'd like fixed in the event logs to ensure good vss copies are made.  

*** Edit - Starting to think Carbonite might just be sloppy with the VSS writers and not leaving them in a great state.  Checked three different Windows XP machines that run Carbonite.  All three of them currently (after being on for a while with Carbonite run a few backups since last reboot) had the WMI Writer in a failed 7 state.  It doesn't APPEAR to be effecting any backups though (Carboonite or local).  

Answer : WMI and SqlServerWriter under VSS writers both have issues, why do they always fail?

That's good stuff!  I'd agree that no errors during the lock up of carbonite says alot.  AV is always something to look at, but it's just not the invasive trouble maker it once was, so I don't often make that my top 5 to look at if I don't forget it all together.  Have my fingers crossed.