I recently saw episode 107 and saw that the opening titles were new and they didn't feature Billy and students getting to class on time. It just showed the title of Head Of The Class and then went into a scene. is that all season 5 episodes start out and not with Billy replacing Charlie and the students racing to class, like the openings for seasons 1-3. Also during the 89-90 season, I know three cast members left, did the new students replace them in the opening theme?
Can some on get back to me on how the opening themes for the 1989-1990 and 1990-1991 season started.

HOTC fan, you read my mind. I know how Seasons 1-3 open, and Season 5, but I have no clue as to how Season 4 opens. If anyone else knows, then feel free to post!

Season 5: The beginning (and just that) of the usual theme music plays, with this digital looking background, and all different types of symbols (for math, science, etc.) floating around. The logo "Head of the Class" appears (in a different font than usual), and then "Starring Billy Connolly" appears. It fades into the opening segment, and the cast credits roll over it. Not as interesting as 1-3.