When Leela enters Bender's dating office, there's a second sign on the door, but when she departs there's only the original sign.
At the end, as Leela and Bender are arguing, the background remains exactly the same when the scene switches from Leela to Bender, even though they're facing each other.
When Fry is having his head sewn back on the chair her is sitting on guess from red and rounded to blue and squared.
The car recovery alien guy wipes condensation from the outside of the car's window. There is no moisture or atmosphere there, too hot and not enough gravity. Any condensation should have been on the inside.
Fry's date says she would kiss him goodnight but she lost her teeth, when in fact she has a full mouth of teeth, but she's just making an excuse to leave.
(at around 20 mins) When fry turns his chair, the back appears in place instantly and then a ghost image moves in to cover it.