I just wrapped a book this morning going to Naperville, IL...and for some reason, the site said that Delivery Confirmation was unavailable for the address.  It looked to be a normal address.  Just seemed weird to me.  I will try to buy it at the post office instead, just so I'll know it arrived.   Has this ever happened to anyone else?

Ive had it happen once or twice.  Usually its something like an abbreviation that the postal system prefers e.g. I live on Saint Charles Ave but on my address it has to be St. Charles Ave or DC would come up unavailable.  If you look on the USPS you can type in the the address and it will show you how "they" want it.  You might want to PM the recipient and tell them to check the USPS to get tht right address format so that E-DC can be used & they can change it on their settings

See the thread here for a similar question and solutions:

http://www.paperbackswap.com/forum/view_topic.php?t=68527

And sometimes it's just a problem with the USPS website not communicating with the PBS website--not an unavailable DC address, just an electronic web problem. Usually trying again later will find the problem solved.

Yes. The person input their address in the system incorrectly. They lived in an apartment building, and didn't give an apartment number.