Episode One - S1-E1
Continuity mistake: When Pete is trying to get the drill back from Ben (before Pete says "I'll give you a fiver if you give me the drill"), the position of Ben's hands on the drill change between shots.
Episode two - S1-E2
Continuity mistake: When Sue gives the house phone to Jake while she's talking on her mobile, Jake takes it with his right hand but he takes it again in his left hand in the very next shot.
Episode Four - S2-E4
Continuity mistake: When Karen is drawing in the airport asking about what other religions are responsible for damaging aircraft, the pencil she has changes colour constantly. Sometimes she doesn't have a pencil at all.
Episode #3.4 - S3-E5
Continuity mistake: When Lance says "This is a bloody joke", he throws his racket on the floor. The racket then reappears and disappears over the course of his following lines.
Episode #4.2 - S4-E2
Continuity mistake: When Ben is serving the puree/meal he created, firstly he removes the lid from the serving dish with his left hand. It then reappears in his right hand. Also the ladle Ben is holding to serve his concoction switches hands for the next three shots.
Episode #4.6 - S4-E6
Continuity mistake: When Pete asks the man if they can have it in writing as they are having a family dinner, the kitchen door is closed, then the shot goes back to the man they are talking to at the front door, in the next shot which returns to Sue and Pete in the space of less than 2 seconds the kitchen door has been opened. (00:01:10)
Episode #5.3 - S5-E3
Continuity mistake: At the end of the episode when Peter has seen Stacey undressed, Sue comes up the stairs and Ben is standing on the landing behind her. The position of Ben's arms is different in the close-up of Sue than it is in the wider shot from from behind Stacey.