Corrected entry: Charlene said that she could remember up to when she picked up the encyclopedia, however when they were retracing her steps, she couldn't remember where it was.
Corrected entry: Phoebe's final is on Friday morning, but when she comes to the Goo-Goo Dolls concert at P3 (on Saturday, according to the posters) she's already received her grade. There is no way her final would have been corrected and her grade posted up that fast.
Correction: Her grade very much could have been posted by that point. I taught a college course and my class had their final on a friday night, We had to have their final exam grades and overall class grades by Sunday morning. So that is the same time period and everyone's grades were done. Maybe the professor had help.
Correction: Charlene remembered walking down the aisle to get the encyclopedia. That doesn't mean she remembers exactly where the encyclopedia was in the aisle. After all, a lot has happened to her since then. What with getting decapitated by a demon and becoming a ghost and all.