A technical error in Cambridge reduces the price of petrol from 107 pence per litre to 40 pence per litre at a Tesco forecourt.

As you can imagine, the queues started to grow quite quickly and it mysteriously took them a week to realise the shocking error. You would be forgiven for thinking the error was discovered by the staff questioning the unusual volume of happy customers going through the petrol station but, oh no, it was only after hearing gloating customers on local radio!

http://news.bbc.co.uk/1/hi/england/cambridgeshire/8276221.stm