i never knew that. i died once and checked my resistances and they were the same as when the scroll was still in effect. i didnt leave/rejoin either.Just remember that the bonus is lost when you die, until you join a new game (or re-enter) though it will still be displayed on char screen.
Nothing tells the character that the bonuses are no longer present.So, at the risk of sounding real stupid, how do you know that you loose the resist bonus if the char screen says otherwise? What tells the player that the bonuses are no longer present?