Having screamed at my computer in work this morning - paypal I hate you, have I told you this? And I mean really hate you - I should have realised I wasn't technologically on the ball.
But really if the scale is not precise enough to recognise a packet of tags then it should know that and allow for it. It's not rocket science. And if it's going to allow you to put through a tagged item it should simultaneously call the assistant to remove the tag or at least warn you - before you set off the alarm on the door.
Having gone there straight from prison I had visions of being back in prison before the day was out. The security guard - young, bored - looked at me suspiciously: I admit I was having a very bad hair day. Or maybe he thought I was just another menopausal woman who'd 'forgotten' to pay.