Thanks for the responses guys.
As I said I have viewed the book using mobipocket reader on my PC and it reads fine but does show this strange character, I`ts obviously a problem with the be-book`s handling of the weird character which kicks me out of the book.
I`m using the firmware version before the latest one as the latest one doesn`t support DRM mobi files and I`ve got a few books in that format to get through
I did contact the site I bought it from and they refunded some of the money but didn`t seem too concerned that there was a problem with the original file.
As I`ve bought the book from another store and it was the same file with the same problem it`s not seller specific.
I think I`m going to have to search through the forum for how to de-drm the book and try and fix it that way.