Why do I lose the properties when a new hdb is created?

I noticed that when someone stopped and started the OPCUA collector to add more tags into the dataset, and as a result created a new hdb file with todays date and the time at which this happened, in the new hdb file and subsequently the views that use this dataset, I no longer see the properties that the tags i had before had. Is there a configuration or something simpler that i am missing here to make it so that these properties are always carried on? (all the properties we had were imported with csv files)