SNAPSHOTPROVIDERFS VSS causes error 12

Greetings!

We are in phase of preparing a document called: BCP (business continuity plan). The idea is to go thru the procedure of restoring one 2008 server in case if something really bad happens.
We have read some articles about how you can achieve a bare metal restore:
https://www.ibm.com/developerworks/m...0Vista?lang=en

So for the restore procedure we would need to have also this command in dsm.opt in our Windows 2008 server: SNAPSHOTPROVIDERFS VSS, right?

But now we are facing some problems.
If we put: SNAPSHOTPROVIDERFS VSS into dsm.opt, and when in the evening incremental backup is started, we receive randomly (one day yes, one day not) error:

11/27/2012 18:18:39 ANS1512E Scheduled event 'INC_DAILY' failed. Return code = 12.
11/27/2012 18:18:39 Sending results for scheduled event 'INC_DAILY'.
11/27/2012 18:18:39 Results sent to server for scheduled event 'INC_DAILY'.

Information about OS&TSM client version:
- Windows server 2008 standard with SP2
- Tivoli storage Manager Backup-Archive Client: Version 6, Release 2, Level 4.00

Any suggestion how we can fix this problem (restarting server is not in option)?

With best regards,