I am getting an error while taking vm backup using VMWare Data Recovery. What can be the reason? Please find the log attached

Observations / Tested following

1) Changed Host server
2) Changed Data store
3) Reconfigured VDR
4) I can create Snapshots manually
5) Problem for all the vm backups
6) Integrity Check completed without any errors

Log——————————————————-
18.02.2013 11:51:39 AM: Normal backup using Backup-Testing
18.02.2013 11:51:41 AM: Created snapshot “_datarecovery_”
18.02.2013 11:51:43 AM: Failed to create snapshot for LDAP-Proxy, error -3948 ( vcb api exception)
18.02.2013 11:51:43 AM: Task incomplete
18.02.2013 11:51:44 AM: Removed snapshot “”