I recceived a book through PBS; as I was reading it, the pages went from Page 264 to page 233.  Page 233 onward was a repeat and kept going to the end of the book.  Essentially pages 233 through 264 were inserted in the middle of the book again.  The story followed correctly.  Can I post this?

Yes. It's a publishing error/mis-print but as long as nothing is missing or cut off (like a margin trimmed too narrow, etc.) it's postable. It's likely a 'signature' that was double inserted. Sometimes one is double inserted and one is missing; that would be unpostable. Other mistakes include upside down sections, ink smears & drops (publisher's ink). All are postable as long as the book is readable and not otherwise damaged. There are any number of discussions about this over the years in the forum.

Publishers will replace books like this if they're newer prints. You can contact the publishing house and let them know you have a copy. Often they're aware there's a batch of similar books out there that slipped through their quality control and they'll send you a new one.

I don't think you would have to alert the person you're sending it to. As a courtesy you could put stickies or something on the pages so it's easier to skip. But it wouldn't be necessary.  If it's WL then you could PM when they ordered and then you could cancel the order if they don't want it. 

Yes, I agree, as long as the book is readable and nothing is missing, printer's errors are postable.

I have had good luck requesting new copies when I've had some that were actually missing pages, requesting new copies from the publisher.