Yup. Had a character die of old age in the Tower of Inverness. He was a ranger who in a panic drank down a potion of Longevity and a potion of Haste (two previous unidentified potions from an earlier random encounter,) during a battle with a basilisk. Sure enough, on the potion miscibility roll, I rolled a 00 and determined randomly that it was indeed the potion of Longevity which was increased. I was immediately aged 150 years by the DM. At which point we roleplayed it that my grandpa showed up, and was promptly petrified. One of those classic 1st Ed moments that i'll always remember...