In the last month this has happened twice. I go to the self check out and a Costco employee approaches me to scan my items. They then ask for me to put in my credit card to make payment. So at this point I have no idea what has been scanned. The last two occasions the male costco employee scans the items in my cart and on both occasions scans the same item twice. Simply by the speed of the way he is checking out my items and not paying enough attention. Talking to other employees whilst doing the scanning. The first time tomatoes were double scanned. The second time Allergy meds were scanned twice. Luckily I noticed and lined up at Customer service to get the errors corrected. Its annoying and wastes my time. I have also had other issues with Costco at the other checkouts. Your check out cashiers are not trained properly and constantly make errors double scanning. Inver Grove Heights, Minnesota.