Other mistake: Even though this is the first time that the kids are being introduced to the "Urkel Dance," Maxine is mouthing the words to the song as she dances.
Other mistake: When Eddie and Carl are out ice fishing, you can tell the background is just a wall. If you look towards the bottom, you can see the line all the way across that would make it look like a wall of scenery.
Other mistake: Eddie drives the car through the front door. This shouldn't be possible. Whenever the front of the house is shown, we see that the porch is several feet above the ground and the only way to get to it are steps that aren't wide enough apart for a car to drive between them.
Answer: It was just cancelled. Read more here: http://www.kellie.de/end.htm.
Myridon