ToME WikiBobbyJim: When moving over lava, you still take damage even when you are immune to fire. EDIT: In addition to the above, fire immunity does not protect you from the death throes of a jumping fireball. There may be other fire affects that also ignore immunity to fire.
SigSegv: I am unable to reproduce this error. Once immunity is set for a player I can kill fireballs or walk on shallow or deep lava without taking damage. What were you wearing/wielding, or using, or activating, or casting that made you believe your character was immune to fire?