[Histonet] weird brownish stuff in AEC slides

[SMITH,REBEKAH FELICIA]

I have yet another question, guys. I've been asking a lot of 
questions about blocking endogenous peroxidase,but now I have a 
new situation. I'm still using the ABC peroxidase method staining 
sheep placenta (formalin fixed, paraffin embedded) for eNOS and 
using AEC as a chromogen and gill's hematoxylin (blued with tap 
water and water with 2 or 3 drops of ammonia) as a counterstain. 
(btw, still blocking peroxidase with 30% peroxide in methanol, 
since my professors are away and haven't been able to order 
anything better) I have the lovely red and blue contrast in most 
parts of my slides, but I also am getting areas of brownish-black 
staining (kinda DAB colored, although I'm not using any DAB). I'm 
not exactly sure where the brown comes from this and whether its a 
problem with my AEC, my hematoxylin or something else. Anyone have 
any ideas? Thanks in advance, y'all have already been really 
helpful.

--
SMITH,REBEKAH FELICIA
"You are a child of the universe, no less than the trees and the 
stars
You have a right to be here and whether or not it is clear to you, 
no doubt the universe is unfolding as it should. Therefore be at 
peace with G-d, whatever you conceive Him to be. And whatever your 
labors and aspirations,in the noisy confusion of life, keep peace 
in your soul.-Max Ehrmann,"Desiderata"