Thank you both for your help. When I get back to Ohio this coming weekend, I will see what I can do and will definitely ask again if the problem persists. I'm thinking of setting up a new drive (thumb) for the accumulation and the analysis, targeting this drive for the accumulation. Indeed, before I left town I did discover that the data was going into another folder, but then could still not retrieve a full set of data. I may have too many dat files in that folder. Were I to create a clean folder or new drive, what would need to be that destination before I targeted it for data accumulation?