I just received a book that has about 30 pages bound upside down.  Can I mark this RWAP and ask for my credit back?  The pages are upside down and reversed in numbering, so it's not just a matter of turning the book upside down and going forward.  I have swapped a lot of books and never encountered this problem before.

Well, it's up to you.

If all the pages are there and you are able to read them ... if it was me, I probably would not RWAP. You can usually contact the publisher, in the case of in-print books, and they will replace a printing mistake book for free.

If there are pages missing, then definitely RWAP.

Generally, for printing mistakes ... if the book is still readable, I would usually consider it still postable.

I've had some where there was randon splotches of ink (not covering text), a repeated section of pages bound into the book (but no missing pages, just extra ones) ... I would generally post those.

I've also received one that was bound with 40 pages missing (a printing mistake) but I didn't catch it in time to mark it RWAP .. but the publisher sent me a brand new copy free of cost so that one ended up fne. I would have RWAP'd it if I had noticed before I marked it received.

Generally, if all the pages are present and readable (regardless of order or annoyance factor), merely a binding error...TPTB seem to favor the not a RWAP route. 

Members report sucess contacting the publisher for a replacement (if the book is still in print).

Thanks for your help.  I marked the book received in good condition and I will try to contact the publisher.