The immediacy of the internet should get rid of that annoying problem when you see a great price in the paper, but when you come to book it, it's always mysteriously sold out, right?

Wrong, or at least in my experience of the much-trumpeted travel website Opodo. Launched in January by British Airways and another eight scheduled airlines, it promised cheaper flights than other online companies in 85 per cent of occasions, as well as cheap hotels and car hire.

Trying to book a Crossair flight to Geneva on Opodo in February costing £112, I found after going through the booking process that the price shown on screen was not available. Despite a call to customer care, in which I was informed there was a 'glitch' in the system and offered a fare for considerably more, the flight was still on Opodo's screen a week later.

Reserving a car on the site on a separate occasion, it turned out that once I had entered my credit card details and confirmed the booking, the cheap price of £110 from Lyon for a week was not available. I had, in fact, reserved a car at the more expensive rate of £143. I had to call customer support to cancel the reservation.

Bruce Treloar, Trading Standards lead officer on travel, said: 'This is illegal, as they are offering something that is no longer available. It is misleading pricing. If it is not available, it should not be there. If it is sold out, it should be removed as soon as it is not available.'

An Opodo spokesman said: 'We have had some glitches because of the exceptional interest we have had in the site. The prices people see on Opodo are the prices they should expect to pay.'

But he added that, because the flight price had not been an Opodo special offer, but came through booking system Amadeus, it had not been possible to take it off the system.

If you have had similar experiences with Opodo, or other online booking systems, drop us a line at escape@observer.co.uk, putting the word 'Opodo' in the subject line.