What is going on with failing classes?

I actually came here to find this thread because I was so annoyed about one of my sims. He was a pre-existing sim self-employed as an archaeologist. I wanted to take it easy to test out the pack, so I started him with only one history major course and one archaeology elective. He went on-time to every class, with homework fully complete and all bars full, completed and submitted an outstanding term paper for the history course, and took the final exam for the elective. I had him study for both courses daily; he raised his research and debate skill from zero to level 4, raised charisma and logic skills, and raised archaeology from level 5 to level 6. He also chatted up the professors and had a good relationship level with them, and went to office hours.

And yet he ended up failing the history course and only getting a B in the archaeology elective. I could _maybe_ understand the B in the elective, but in what world would you ever get an F after attending every class, doing all homework, and turning in an outstanding term paper?