Humm, it's like, i'm not sure here... gloams, souls'n dolls can be froze, can't they? Like frozen yoghurt ^^ "Yog-hurt" xD

But it's like, i play old d2lod, idk if it's changed in the quick cash-in version.

But it's the holy freez is on good level wise, then its slowing them by a big degree, so it could as well been as if they are frozen, they move so slow. The slow dance. Also if decyptify is in action.

Yeah, it may be differet in lod versus d2r.

Well in my Guide: M'Avina's Freezing Arrow build years ago for LoD, this was the information added... however, I assumed it related to all Cold damage like Glacial Spike and Holy Freezing... remember, this is old information and not related to D2:R, it applied to LoD:

"Freezing Arrow:
Hell Difficulty: You can not freeze certain monsters because they have "Chill Effectiveness 0".
Souls & Gloams (Willowisps), Bone Fetish (dolls) and Blood Lord (Death Lord only "dual-axe-weilding brutes found in WSK & Throne)
Thanks to Faelwen for providing this information and links:
http://www.battle.net/diablo2exp/monsters/act3-willowisp.shtml
http://www.battle.net/diablo2exp/monsters/act5g-willowisp.shtml"

NOTE: I doubt the links are active, but maybe this information could be useful.