Guys, it's NOT from macros.

It can happen even if you manually target....happens to me all the time. Not sure if the game is dropping the tanks packets or mine, but you go to Cure the tank, and Cure lands on you...causing you the fun of double curing.

Happens to me more in dungeons when switching from casting a DD spell on the mob, turning CS off> targeting tank and curing...I target tank directly in party list. If I do it 'too fast' Cure lands on me and not the tank. It can also happen if you go to change party member targets to heal (happened to me today in Haukke HM), have tank targeted, needed to heal a dd, targeted DD, cast cure and cured myself causing me to have to re-cast real quick on DD.

It does seemingly only happen if you switch targets...so Switch from tank to another party member it can happen or Switch from Mob to tank same thing. I think it's because we can change targets/start healing faster than the game knows we did it. It SUCKS royally though.

I don't know why it happens, but it is a known issue amongst WHM's. Don't know if SE is going to fix/can fix though.

But it is NOT a macro script error. You can replicate the same issue without using a macro.