This episode was produced for the third season but didn't air until season 4. Though several cast changes had been made in the interim, this episode aired without the newly-added season 4 characters, and the old characters from season 3 (who had previously been written out of the series) reappeared without explanation.
In the syndicated version, the plot line about Mr. Moore advising Alex is not seen and the plot line with Arvid trying to impress a girl is not a flashback.