I posted one of my books I'm guessing at least 6 months ago, and have now had to repost it twice.  Its just removed from my book shelf.  I have a very small shelf, only 7 books, as lately all the books I am posting are WL.  Any idea?

Are you getting your PBS emails?  If it is requested and you do not respond, it is removed from your bookshelf.  Sometimes the emails are treated as spam by your server or your filter.  Go to your transaction archive and your club communication file, both a link at the top of your main account page.

And if that is the case, add librarian@PaperBackSwap.com and NoReply@PaperBackSwap.com to your email safe sender list so the emails will be delivered to your inbox on your email account.

Are you letting requests time out?  YOu have to check your account regularly. If you aren't respondign to book requests then it removes the book from your shelf.  They will suspend your account if they see a pattern of unanswered book requests.

If you check your transaction archive, that should give you a pretty good idea of what's going on.

I'm on here a thousand times a day.  It is a book that has plenty others posted so I'm sure I am no where near the top.  I will check my archive just t be sure though

I had that happen with a book.  No missed requests or messages--it just mysteriously disappeared from my shelf.  Lucky for me, I happened to notice it and there were very few copies in the system, so it still made it through FIFO.

ETA: On further review, I see that it had been in my transaction archive earlier on.  Looks like someone requested the book, cancelled within the first hour (the buyer's remorse period) and the book was deleted rather than going back on my bookshelf.