from patch 1.0.6 the bugged mobs that didnt spawn that i pulled from others and myself were:
Trophy Hunting (HC yellow rares):
Savage Rockworm
Rockworm

A Rare Phenomenon (SC yellow rares):
Sand Dweller

We Are the Champions (HC blue champions):
Subjugator (spawns but doesnt tick)
Plaque Swarm (wasnt bugged before)
Fallen Cur (wasnt bugged before)
Savage Rockworm

Champion's Collection (SC blue champions):
Subjugator (spawns but doesnt tick)
Plaque Swarm (wasnt bugged before)
Fallen Cur (wasnt bugged before)

from the patch notes: http://us.battle.net/d3/en/blog/8414570/#monsters
it says they fixed the sand dweller, fallen cur, and the plaque swarm

this still leaves the savage rockworm, rockworm, and subjugator in the unknown. haven't downloaded the PTR yet so i can't verify anything as of yet. anyone want to verify any of this?