Episode #4.1 - S4-E2
Continuity mistake: When we first see Gavin and Kenneth, Kenneth is holding a fork with nothing on it. In the next shot, a sausage has appeared on the fork. (00:05:25)
Episode #4.3 - S4-E4
Continuity mistake: At the end of the scene where Pauline is talking to Michael at the bar, Pauline puts an empty glass on the bar and says "keep them coming". Mateo picks the glass up, and puts it under the bar. In the next shot, the glass appears back on the bar side.
Episode #4.6 - S4-E7
Continuity mistake: When Jacqueline, Gavin and Kenneth meet Sir Henry to find him listening to his iPod, Jacqueline, Gavin and Kenneth are all looking at each other. In the next shot, the three are all looking at the Sir Henry.