Use base stats, not current stats
Use base stats for all stat increase/decrease purposes.
Not sure if I should post it a bug or RFE... seems more like a bug to me.
I think base stats instead of current stats should be used for increase/decrease stat calculations. It's a quick way to get rid of many tactics that could be considered "scummy", like getting sick on purpose, or in the extreme case getting stats way too high with ring of weakness/herbs/potions of exchange. Also it sounds like and easy change to make, but I could be wrong here ;).