I'm not sure when you say "I have connected the fully loaded TBS with sounds" you mean that you are connecting to your sound card, or if you mean you are loading a .tbs file from your computer.
But as Jürgen says, TBS Flash doesn't know anything about the sounds on the Benedini sound card, it only knows about whatever sounds you give it from your computer. That doesn't mean there might not be sounds on your sound card, as is the case with you. But you can not read those sounds from the sound card. When it comes to sounds and the Benedini, the direction is only one way: from the computer->to->the sound card. You can't go the other direction and so yes, TBS Flash will show blank sounds even after having connected with the special cable to your sound card.
Now in TBS Flash you can save all your sounds to a ".tbs" file on your computer, and then you can load the file later and all the sounds will appear in TBS Flash in their appropriate slots. Then you would write those to the sound card.
But if you never saved a ".tbs" file to your computer, then you just have to start over by loading each individual sound into TBS Flash. Write it all to the sound card, and save a ".tbs" file to your computer as a backup.