I guess, reading your macro, that you aren't using an FTL setup? Otherwise your castsequence would keep resetting after the first spell due to the reset=target condition. I use the FTL setup, and use reset=combat. (Should i also include a 'time' condition in there too)?
Do you think the constant switching checking of the target to the leader from the slaves is resetting the auto swing timer? its so frustrating when the slaves just stand there being hit when the runes are on cool down.