In the earlier "Miss Bliss" episodes of Saved by the Bell, Zack's dad's name is Peter and we know that Zack's parents are divorced. Yet, in the later episodes with Kelly, Slater, and Jessie, Zack's father's name is Derrick, his parents are together, not to mention his father is played by a different actor. Also, in the Miss Bliss episode where Zack's dad is dating Miss Bliss, Miss Bliss told another teacher, Tina, that she didn't know him that well, (before she found out that he was Zack's father), so she told him her name was Tina, the other teacher's name. However, in the very next scene, Zack's dad comes in to see Miss Bliss, and calls her "Carrie", her real name. If Miss Bliss told Zack's dad that her name was Tina, why would he call her Carrie?