Continuity mistake: When Kenneth Williams calls for a doctor during the cruise party, Kenneth Connor bumps into him and you can see that Williams is going to fall to the floor, but when Williams bumps in the chef, he is now standing up.
Continuity mistake: When chef Wilfred Haines is making the cake for the surprise party, the amount of mixture on his face changes between shots.
Continuity mistake: When chef Wilfred Haines picks up a dessert to have a look at it, you can see he is going to pick up the dessert fourth from the right of the bowl, but when the camera pans in, he picks up the dessert second from the right.
Continuity mistake: Before doing a speech at the party at the end of the film, Sid James is handed a message, which he puts in his pocket twice.
Continuity mistake: When Lance Percival gives Sid James a slice of the International cake, the slice is large and triangular, even though you can see the hole it was cut from is thin and rectangular.
Continuity mistake: When Sid James is trying to make his favourite alcoholic drink, an "Aberdeen Angus" he discards the wrong mixture into a vase. You see that the vase is filled up to the top but then in the next shot the vase is only half filled and is a different colour!
Continuity mistake: When Kenneth Williams sprays Sid James with the soda siphon, in close-ups he is holding Sid's head, but in the long shot, he isn't.