I don't think dirty glass or lines are to blame. Beernik you mention hops and it gets me thinking of alpha acids that might also be present in the essential oil of Costus root (which smells blatently of wet dog). Have you ever smelled hops that clearly had the aroma on their own?
I'm inclined...
I really believe it has nothing to do with being stale. I get the flavor and aroma from MANY beers, some that I knew were FRESH ie straight from the brewery to my door