When Laura tells the lie about catching her husband with the babysitter, the strap on her purse changes from an angle to straight between shots.
When Urkel rushes out of the house, he leaves the door partially open. When Carl then comes over to close it, it is open further than Urkel left it.
When Steve is on stage at Club Buff, he makes Laura aware that her mother, grandmother and aunt are also inside the club. Laura is shown sitting with Maxine and KC. When Laura tries to hide under the table, Maxine and KC suddenly disappear.