Why does my barcode scanner add incorrect items to the cart?

[cjpletcher]

We're having an issue with a scanner. Sometimes when you scan an item, it'll add a completely different item to the cart. A particular barcode will be working fine, then it'll add a different product to the cart a few times, then it'll be working fine again. One of our managers noticed that the wrong item that's added to the cart is usually something that he had been trying to scan just a little while ago. He'll scan something, the scanner will beep, but nothing will show up in the cart. Then a little while later the thing he had tried to originally scan will show up in the cart instead of another product he's trying to scan at the moment. This has been happening a couple times a day for the past few weeks. Are the scanners able to store any data in them? Maybe when we do the initial scan, we're storing that barcode in the device and it ends up getting put in a cart later that day.