IPhone :: Cannot Delete Certain WMA Audiobooks From My 4

I have certain audiobooks that will NOT delete from my iphone.They all happen to be WMA audiobooks from Overdrive Media Library. When connecting my iphone to itunes, they were visible under "Books". I deleted them and they were removed (but only from books in iphone in itunes). [Side note- these audiobooks were never in my itunes library. Through Overdrive Media Console, they transfer directly to your iphone.]Upon searching on my iphone in the "spotlight search", the audiobooks still came up in search results, and i could still play them. So they are still trapped on my iphone! Interesgtingly, these trapped audiobooks are not located in any traceable location. They are no where in Music anywhere( ie artists, song, album, etc). And they are not in Audiobooks under the More section(not in compilations, not in podcasts, etc). They only come up in "spotlight search".

And the best part,after hours of trying to figure this out, I accidently wiped out all my music and other normal functioning audiobooks (i was experimenting with "Sync", thinking maybe that would help), and everything was wiped out, EXCEPT THE 3 WMA Audiobooks that i was trying to get rid off!They are still on my iphone- like cockroaches.

Info:
iPhone 4, iOS 5.0.1