So I had my first book go missing today. I have my mail go to a PO box because things get misplaced at the condo complex where I live. Anyway, I printed the tracking information from PBS and took it to my PO. The clerk couldn't find the book and brought me her own print out. My book was sent from a member in Oregon. The PO's intranet print out says it originated from Suwanee, GA. Does anyone know why that is or if it means anything?

It sounds to me like it wasn't scanned at the originating PO but scanned in GA.  Sometimes they go on little detours.  I asked my PO lady about this and she said they don't even look at the address if there's a barcode to scan. They scan the bar code that prints out under the address on the PBS label.  So if that's wrong for some reason-maybe it was entered wrong into PBS, maybe the printer messed it up a bit-it might bring up the wrong city and that's the bin it goes in when sorting.

I know the game books I mail with DC are only scanned at the local PO when I bring them in and buy postage there. If I just put them in my mail box or the blue box-then they aren't scanned until sometime later down the road. 

When you purchase the DC through PBS it goes into the USPS system as originating in Suwanee, GA because that's where PBS is located.  When you look at the "details" of the transaction in the PBS system the city and state are replaced with your own.  This is only for the original "information received" entry.  Once the DC barcode actually gets scanned at a USPS facility that information shows up fine.

You can test this yourself by looking at the details of any book you've sent or received through PBS that had a DC#, then inputting that same DC# on the USPS site to see the difference.  Even if the book started out in Hawaii, on the USPS site that first entry will always be Suwanee, GA