I was doing a Hall's of Orig. and during the trash before Rahj. i clicked on the Non-elemental and the picture for him, literally took up the whole screen, and took away all my spells in the action bars.
this also occurred during the Rahj fight when i clicked the light well. (yea unbelievable) but the light well took up the whole screen.
doesn't give an error. just some Mob's and intractable items take up the screen.