I logged in using my Aco today (in Payon Dungeon), and I haven't been able to use "Heal" on the undead. It worked fine yesterday, in Payon and in the prison, but not today. I checked, and I can use it on myself/other players, just not on monsters. I activate the skill and get the targeting cursor, but if I click on the zombies/skeletons, the cursor turns back into the standard attack cursor. If I click on a player, it heals that player. I even tried it on a Poporing, out of frustration, but it still didn't work.
Has anyone else had this problem today? (I'm guessing not, since several searches didn't turn up anything) Is it just something blindingly obvious that I'm doing wrong, but just can't see? (Like when I logged in with my Archer and couldn't attack because my arrows had somehow become unequipped >_< )