Problem with Recovery of Block Based Backups via NMC

Hi,

I have a problem with a recovery of Block Based Backups via NMC. Environment Description: NetWorker Server 8.1.1 (SLES) with locally installed NMC and a NetWorker Storage Node 8.1.1 (Windows Server 2012 x64) with connected Data Domain DD160. Drive I:\ is ONLY backed up every evening via BBB to DD device, no regular filesystem backup. Now I have to restore a directory...

Here a mminfo from backups of that Storage Node:

netwrk01:/nsr/logs # mminfo -q "client=XYZ" -r "name,savetime,level,sumsize,volume" -ot

name                            date     lvl volume

...

I:\                           23.08.2014 full 439 GB FAHRO.002

I:\                           25.08.2014 full 437 GB FAHRO.002

I:\                           26.08.2014 full 437 GB FAHRO.002

I:\                           27.08.2014 full 405 GB FAHRO.002

I:\                           28.08.2014 full 407 GB FAHRO.002

If I try to recovery via NMC Recover button ad choose client XYZ, NMC shows me some general information like OS, NetWorker version and earlierst / latest backup... Everything's fine so far. But in the "Available Recovery Types" section I only get "Filesystem" with 15 backups (even without traditional backup!) and "Snapshot Manaagement" with 0. No type "Block Based Backup". No chance to recover any data, because if I try to restore a Filesystem recovery type, I get a message "No backups found for this client at this time."

Any ideas how to recovery in this case?

Regards

René