Decrypt SD


Traveler 34122
I have a few SD recordings I wish to transfer to my PC but one of them does not have the decrypt option against it in the WebIF. If I download this file via the WebIF, it does download but isn't decrypted.
The other recordings do have the decrypt option available and, providing I decrypt first, when downloaded, play just fine on my PC.

The recordings have been made weeks ago but why no decrypt option on just one of them? What can I do to decrypt this troublesome recording?

edit: I have reset the DLNA database and all is well now. I have the decrypt option. No idea what happened.