gosh you're crazy/hypocrital if you're telling him that taking AP Calc was a bad idea b/c he's "not interested"... especially on an ivy league forum - come on, top colleges look for the tough courses! we all know that - get over it!
apfreak - I'm sorry about your exam problem... I assume you mean a quarter/midterm exam...obviously not the actual AP exam b/c we all know that is in May... I think a letter will be just fine if all of your other grades are strong and you have otherwise maintained a strong record.
(though i'm only a senior in HS, but that's what I think...)