During the musical number, the Robot Devil pulls Bender's arm off and promptly kicks him down a hole. However when Bender lands his arm is still attached.
Bender gets a symbol welded on to his body. When he welds something on to the spaceship, the symbol disappears, but reappears in the next scene.
When everyone is dining out and Bender wants to hug, Hermes changes seats.
When Bender and Fender enter the robot party room, they walk through a door, yet the buttons to the side indicate up and down which only an elevator would require.