Like many others, I've seen the "Dunwich is a Ghost Town" phenomenon as soon as you add a small box expansion.
Given that I'm a lazy bastard who doesn't want to actually sort out of his decks every time, I've found it easier to simply leave the decks for all the expansions in each stack and then simply ignore any cards drawn from the "wrong" expansions. One solution I've thought of while maintaining my laziness is to simply buy a second set of Dunwich Horror mythos cards and add them to the deck. Would that fix the problem? Or just skew things further?
Alternatively, I've thought about separating Dunwich Horror mythos cards into a separate deck and then using some other method (die roll?) to determine which Mythos deck to draw from.
Thoughts?