 Being the last episode written, and the fact that the series had stretched the budget at that point, "Duct Soup" turned out to be the 'bottle show', a cheap production script that replaced the initially more expensive story that was written, Identity Within.In Series 7's bonus features, Craig Charles mentions one word has been dubbed over in the scene where he tells his story about him developing claustrophobia, as it turns out this word was left un-dubbed on the first VHS release of Series 7 and is, in fact, 'Fuck'.Lister's claustrophobia is only mentioned one other time within the Red Dwarf series, in the episode "Confidence and Paranoia" when Lister and his Confidence are outside in space suits.