I finally heard back from Lulu - they say they got a few undeliverables and a few addresses not found. I don't think for a second that folks were unable to provide their own addresses, so "address not found" is a bunch of nonsense as far as I'm concerned.
Those that haven't yet received theirs - you should get an email from me in the next couple of days on how you want to resolve it, the options being either "try again" or "refund". Another option is, of course, double check the address you gave me, but I don't think for a second that's gonna be the issue.