Continuity mistake: When Niles is drunk in Frasier's appartment, he puts a six-pack of beer cans on the table by Martin's chair. The pack has changed position on the table later on when Frasier is talking about empowerment, without anyone touching it.
00:09:15 - 00:10:35David Mercier
Continuity mistake: At the beginning of the show, while Noel is getting Frasier to sign his Star Trek petition, Roz puts a blue plastic cassette into the machine to Frasier's left. During the scene it changes to a black cassette, without anyone touching it, and at the end of the scene Roz walks off with a blue cassette in her hand.