Maybe now you are just at a level that only the strongest spawned creatures give experience? I was level 35 or 36 when I did that section, but don't recall what I got, if anything, for experience.
As far as I know it is just the level difference that modifies the base experience points for a particular creature. I suppose you could try equipping a couple crappy weapons, and see if you notice a difference.
I think there is a minimum experience value for the opponents in Keara's headquarters, as someone was able to
reach level 40 there.
