I am not sure if this is the way it is supposed to be, but from my memory the invis mechanics were pretty accurate prior to the aggro change patch. Unfortunately classic planes raids are the least vivid in my memory since it's been so long. This is the best I can recall it, but not sure if I'm even accurate.
[You must be logged in to view images. Log in or Register.] Sorry for no evidence, but perhaps it's still helpful.
Chests = See invis
Spite Golums = See invis
Loathing Liches = IVU works
Abhorrents = Invis works
Scorned Banshees = IVU works, Sees through sneak/hide
Forsaken Revanents = IVU works
Rats = Invis Works
Ashenbone Drakes = IVU works
Clerics of Innoruuk = Invis works
Kira's = IVU works