
Continuity mistake: When Pete eats Bird-man, Bob is with the crew in the cargo bay. When they run away, Bob disappears. (00:27:00)
Rimmerworld - S6-E5
Continuity mistake: When Kryten, the Cat and Lister teleport when the ship is disintergrating, Lister's locks are over his right shoulder. When they arrive, his locks are behind his back. (00:12:40)
Continuity mistake: When Lister is choking the Cat, he says 'give me a break, Rimmer'; at this point Rimmer is looking at the Cat and Lister, yet in the next shot he is looking at Kryten. (00:22:50)

Continuity mistake: The bottle of chloroform Kryten uses to take Lister by surprise appears from nowhere. (00:23:30)

Continuity mistake: When Ace drives the bike out of the shed, the piece of wood is between the front wheel and the handlebars. In the next shot, the piece of wood is resting on his arms. (00:03:25)

Continuity mistake: When Rimmer's mother is talking to him while he is hung upside down, she is stood about a foot away from him in one shot, then in the next she is about three feet away. (00:01:45)

Continuity mistake: When Lister and the Cat first see Lisa Yates on the screen, their shoulders are together. In the next shot there is a wide gap between them. (00:18:30)

Emohawk - Polymorph II - S6-E4
Continuity mistake: The Cat's earrings disappear when the emohawk attacks him. (00:20:00)
Continuity mistake: When Lister and Rimmer talk to Holly at the disco, Lister's arm is on the table. When the camera angle changes, it is on his lap below the table. (00:21:15)
Continuity mistake: After the future Kryten cuts off The Inquisitor's hand with the chainsaw, he kicks the glove which lands about 7 feet away from Lister. In the next shot Lister simply bends down and picks the glove up from in front of him. (00:13:45)
Continuity mistake: In 'Thanks For The Memory', both Lister and The Cat injure their left feet when they drop the gravestone; but The Cat is seen to be wearing a plaster cast on his RIGHT foot. (00:12:10 - 00:27:00)

Continuity mistake: When the gunman ties the cable to himself, he walks past a window, then in the next shot he is stood in the centre of the same window. (00:15:40)

Continuity mistake: When Rimmer gives Hollister the directives to sign, he holds the clipboard in both hands. In the next shot his left hand is under the first page. (00:02:15)
Answer: The cello is a large four-stringed instrument, which, when it is played, stands vertically on the floor between the player's legs (assuming they are seated). If it is to grow as large as the other instuments mentioned will, it would require a rather unseemly lack of femininity to be able to encompass it with the legs.
Rooster of Doom