Took my first step into an instance just last week, went to RFC with my five shammies.
Started out pretty well, macros all working, totems doing their jobs, snakes going down nice and fast, me taking little damage. Then I came to the first earth elemental, I remembered that they were immune to nature damage so was gonna have to melee him but I#d set up and tested healing macros so I didn't think it would be too much of a problem. Set up totems, used a single ligthning bolt to pull him, he came running in and, for reasons that I still don't understand (since I'd unbound autorun from all but my leader), two of my girls ran off into the lava, and the other three got pounded into mush ;(