There is a quest somewhere in dragonblight where you have to let a worm (i think) hit a char until he's poisoned, scrape the poison off, and repeat until each char has x poison thingies. As my healer is a priest, the natural thing was to put a shield on the toon that was being beaten to death - to avoid healer aggro. Strangely whenever my mage started doing this, a (seemingly) random WoW window would close down. I was going mad trying to figure it out, until i occured to me tha alt-F4 might not be the right choise for shielding my mage (had slave healing on F1-F4, with lots of key modifiers).