I just gave one of the Dev Guys a headache. I just found a big ass issue and it's in a core Math library. Oh, this one's a doozy. It's curious that it's never manifested a symptom before ... which was one of his arguments for not bothering with it - if it hasn't shown up by now, it's probably really really rare.
Dev Lead says to try risk assessing it and fixing it anyway.
... s'like, Sorry bub. =S