EN World doesn't have a store. If the way Lulu presents its services as being sold by EN World as opposed to being sold by them, then there is misrepresentation on their part. We merely allow them to print and sell our IP. Same goes for the PDF stores - RPGNow, Paizo, etc.
I fundamentally disagree with the way these stores tend to imply to you that they're just the "messenger" and that their foul-ups are in some way the IP owner's fault. They're entities licensed to sell you IP, but they should make it clear that they are selling it to you and are wholly responsible for any transaction that occurs between you and they. I very deliberatley don't sell anything to anyone directly (although I do try to make sure the customer - who is an innocent party - ends up happy, even at my own cost).
The correct analogy is a local bookstore who sold you a book with soiled or ripped pages.
So, in short, it's Lulu's fault, but I'll make sure you end up happy.