I've had this problem when playing sc2 as well, and if I play for any appreciable amount of time, even disabling automatic graphics switching doesn't help.
I've actually talked to Blizzard about this (I thought it was a problem confined to SC2), and they indicated that Apple was working on a fix for this.
I've actually talked to Blizzard about this (I thought it was a problem confined to SC2), and they indicated that Apple was working on a fix for this.