Hey Guys,
Fresh from the DPM blog: http://blogs.technet.com/dpm/archive/2010/04/14/new-dpm-solution-dpm-encountered-a-retryable-vss-error-when-trying-to-protect-a-hyper-v-vm-that-has-forefront-tmg-2010-installed.aspx
Whenever you have the following error:
Recovery point creation jobs for Microsoft Hyper-V \Backup Using Saved State\W2K8-R2 on protected_VM have been failing. The number of failed recovery point creation jobs = 1.
If the datasource protected is SharePoint, then click on the Error Details to view the list of databases for which recovery point creation failed. (ID 3114)
DPM encountered a retryable VSS error. (ID 30112 Details: VssError: The writer experienced a transient error. If the backup process is retried, the error may not reoccur.
(0x800423F3))
Then check out it out @ http://support.microsoft.com/?kbid=981948
Watch out, it is not a hotfix, but a workaround!
Cheers
Mike