Broodmother fight won't start. Bugged?

I'm just about done with my latest replay of DA:O and I have come to the broodmother fight. However, after the cutscene, nothing happens. I can see the broodmother and shes alive however the fight never starts. In fact, I can leave the area and move on with the quest no problem. Its as if I've already beteen the broodmother except I can clearly see that shes still alive. I have never had a bug like this before. Anyone have any clue what could be causing it?