Disappearing Product

[BJH]

Hi I would be realy grateful for any help on this one. Here's the URL of our site www.spmodels.co.uk. If you add the 21st Century P38 Lightning to the cart, (first section and the only product) the product appears in the basket. However if then disappears when you go to checkout. Other products work OK. Any advice would be gratefully received.

Regards

[jont]

Doing the same for me in Firefox. May be easiest to delete the product and start again.