[b37] Minibosses in limbo

[grmblfzzz]

Twice now I've encountered mini-bosses (first Drolem in Tannens tower, then a randboss in the downstairs room of gorbat bastion), that are "invisible". By invisible I mean I can't see or interact with them in any way, aoe's don't hit them, can't inspect them. They don't seem to act, but their incidental effects happen (gloom on one of these randbosses). Drolem appeared back in the normal game after about 40 turns of resting after killing Tannen, but these randbosses are just stuck in limbo forever it seems.