Continuity mistake: The layout of Frank and Carol's house is inconsistent with the exterior shots. The driveway as seen from their backyard is more shallow and narrow than what is shown in the exterior shots, and the stairway to the left of their front door has a window halfway up, but the exterior shot shows a low section of roof that would completely obscure any window.
Factual error: When they do the opening credits with all the characters, it shows them at an amusement park. It is Six Flags Magic Mountain. At the very end of the opening, they show Six Flags Magic Mountain as if it were next to a beach. You can tell the water was computerized since Six Flags is no where near the ocean.
Continuity mistake: In season 1 Dana turns 16, then in season 3 she is 18, yet they are only celebrating their one year anniversary.
Answer: According to the SBS website, Brendan's disappearance was never really explained. He just kind of faded out. He was hired as the cute "little" one and as he got older he wasn't as cute. When the Lamberts had the little girl, they got their cuteness factor back and didn't need as many kids around.