Well, sure enough, landing spells on immune monsters was confirmed to be a bug: http://www.bluegartr.com/threads/112...=1#post5482810

With their usual misplaced priorities, the dev team is of course working to "fix" this, thus making the most hated ability in the game even more useless. Oh, and they apologized for it not being completely useless to begin with, much like how they apologized for sambas working on pets. Thanks guys, we knew you cared.