Eurotunnel gave me a scare yesterday. Suddenly they wanted to charge me £43 in addition to the £43 I already pay to cross the channel as a frequent traveller. It looks like a bug on the website. By golly, I'm sure it's a bug on the website! But it specifically says they are going to charge me two lots of £43, and the same coming back. I hold off booking.
Today I had another look - Lo and behold, the extra £43 has gone away! Yay! So I book for a reassuring £0. We're off to France!