Just been to my local Asda - Nuneaton. They seem to be having trouble scanning a new line "Dairylea Dunkers Ritz Cracker 4 x 46g".
They are on promation for £1 instead of £2.10, but at the tills they scan at 4p. (if they scan at all! They were playing up so much I ended up paying 4p for 1 pack and got the other for free!)