VSS problems on Windows 2008 SP2

Hi,

I have a VM running Windows 2008 SP2 that I cannot get Veeam to backup.
It seems to be a problem with VSS:

C:\Users\administrator>vssadmin list writers

vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool

(C) Copyright 2001-2005 Microsoft Corp.

Waiting for responses.

These may be delayed if a shadow copy is being prepared.

Writer name: 'System Writer'

   Writer Id: {e8132975-6f93-4464-a53e-1050253ae220}

   Writer Instance Id: {0c3c3596-b840-459e-9202-4a510fadb686}

   State: [1] Stable

   Last error: No error

Writer name: 'FSRM Writer'

   Writer Id: {12ce4370-5bb7-4c58-a76a-e5d5097e3674}

   Writer Instance Id: {317e1b5f-736a-4f5f-8ac5-bbb09e1cdcac}

   State: [9] Failed

   Last error: Timed out

Writer name: 'ASR Writer'

   Writer Id: {be000cbe-11fe-4426-9c58-531aa6355fc4}

   Writer Instance Id: {db368bee-a0b7-46ee-9c46-92e880aa526f}

   State: [1] Stable

   Last error: No error

Writer name: 'Registry Writer'

   Writer Id: {afbab4a2-367d-4d15-a586-71dbb18f8485}

   Writer Instance Id: {dc7826c1-d95b-4720-a5c0-e2049277192e}

   State: [1] Stable

   Last error: No error

Writer name: 'COM+ REGDB Writer'

   Writer Id: {542da469-d3e1-473c-9f4f-7847f01fc64f}

   Writer Instance Id: {30686bd1-9b15-4f59-987b-671eabe8685c}

   State: [1] Stable

   Last error: No error

Writer name: 'Shadow Copy Optimization Writer'

   Writer Id: {4dc3bdd4-ab48-4d07-adb0-3bee2926fd7f}

   Writer Instance Id: {6190a031-4bb5-4a26-9168-0500636e3c08}

   State: [1] Stable

   Last error: No error

Writer name: 'WMI Writer'

   Writer Id: {a6ad56c2-b509-4e6c-bb19-49d8f43532f0}

   Writer Instance Id: {104aa52e-1441-4a97-b332-beeb58b2a7eb}

   State: [9] Failed

   Last error: Timed out

Writer name: 'BITS Writer'

   Writer Id: {4969d978-be47-48b0-b100-f328f07ac1e0}

   Writer Instance Id: {f69bb1ae-4c09-41ad-8335-aa11a1bb3331}

   State: [1] Stable

   Last error: No error

And the Event Viewer on the machine shows:

Event ID: 12297

Volume Shadow Copy Service error: The I/O writes cannot be flushed during the shadow copy creation period on volume \\?\Volume{33c81305-5b5c-11de-b184-806e6f6e6963}\. The volume index in the shadow copy set is 0. Error details: Open[0x00000000], Flush[0x80042313], Release[0x00000000], OnRun[0x00000000]. 

Operation:

   Executing Asynchronous Operation

Context:

   Current State: DoSnapshotSet

Event ID: 12341

Volume Shadow Copy Warning: VSS spent 61 seconds trying to flush and hold the volume \\?\Volume{4d9d0013-9968-11df-b2d3-005056886dfd}\.  This might cause problems when other volumes in the shadow-copy set timeout waiting for the release-writes phase, and it can cause  the shadow-copy creation to fail.  Trying again when disk activity is lower may solve this problem. 

Operation:

   Executing Asynchronous Operation

Context:

   Current State: flush-and-hold writes

   Volume Name: \\?\Volume{4d9d0013-9968-11df-b2d3-005056886dfd}\

Restarting the server and WMI and FSRM services does not help.

Any ideas how to fix that?

Thanks a lot!