there are 3 kinds of chests, as soon as a class try's there inspect message, they will get a message if it isn't the type they can open. then they need to STOP if they keep trying another spell, it will go off.
mine says "that only works on cursed" when i get that message, it means is another classes type.
chest can also have illusion potions, augs, gems.
they need to re work them ;-)
when LDoN first came out, you would find 1 or two in each instanced, now you can do 10 instanced and not see one. oh, i think if there is an aug in one, it is normaly +1 more than the normal augs for that lvl in the instanced.