Again, I apologize for reviving an old thread. I recently bought a barcode scanner and receipt printer, and have gone through threads here at TD.
The way around this is to assign an ID to each player. You MUST have leading zeros. So for myself, I am ID 0001. My membership card (or whatever you want to call it), has 0001 for the barcode. DO NOT make it just "1". If you do, any person that has a 1 in their ID will come up, and you will be back to square 1, searching multiple people.
John.