Continuity mistake: As Daria and Jane are talking to each other in front of the lockers in the hallway at school, the locker to the right of where Daria is standing is locker #307, then shows it as #104, then #307 again.
The F Word - S4-E5
Continuity mistake: When the kids in the classroom are cheering, the map of the world on the wall shows South America slanted a bit sideways, but shortly after, when the class is over and the kids start to leave, South America is now shown the proper way.
Factual error: The roulette game on the boat has some mistakes in it. First, the line of numbers 13, 14, 15 is all the opposite colours of a real roulette game. Then, when showing the game from a farther angle (where you don't see the numbers), many squares are the opposite colour of a real gameboard.
Continuity mistake: In the living room scene (while Quinn is playing Operation and Daria is sitting on the couch), the phone and notebook appear to swap positions throughout the scene.
Fair Enough - S2-E10
Continuity mistake: When the Morgandorffers are in the car on the way to the fair, the camera is on Helen and many red houses are out the window behind her; then instantly the camera is on Quinn (same side of the car behind Helen) and all you see out the window is trees (no red houses at all). Then instantly the camera is on both Quinn and Daria (in the back seats) and now the scenery behind Quinn is all red and blue houses and barely any trees. Basically, the scenery out the passenger side's not consistent.