I have a copy of a travel book, Costa Rica, A Natural Destination, third edition.  When I typed in the ISBN number to list it, the book did not indicate that it was the third edition, and did not have a publication date, and did not have the same cover.  So I suspect that the publishers used the same ISBN for different editions of their book.

This would seem to be a problem if I were buying a book, because it's important to the reader to know what edition of a travel book they are buying.

Is there a way for me to indicate that this is not the exact same book that PaperBackSwap lists for that ISBN number?

Normally, you can do a data edit on the pull down Other Options menu.  But as this is a listing for a book that probably has already been posted and swapped, the edit might not be accepted.  This is an issue that you really need to ask a data edit team member.   You may need to list it with a short ISBN, as if it does not have a ISBN.  
 

Actually, it is common for travel books to reuse the same ISBN for several different editions/publication dates.  There is no way to edit a PBS listing to guarantee that you will get a specific edition or year, since the PBS listings are meant for members to get any edition of a book as long as title, author, ISBN and book/binding type match.  Unless it says in the title "XX edition" you are not guaranteed the publication date listed in the PBS listing.  (And title changes are only very rarely ever approved; only when a book has been shown NOT to have ever have been published with the title as listed on PBS are title changes allowed. So submitting a Data Edit adding the edition date to a title is not encouraged, as it would most likely not be approved.)

Members who want to guarantee that they receive a particular edition with a specific publication date need to make a Requestor Condition (RC) when ordering a copy of that book. Adding an RC is the site's method for members to utilize to be able to order books with special qualifications needed above and beyond the PBS posting conditions (such as a specific publication date or one particular edition of a book when the ISBN has been used as a general ISBN for all editions of a book.)

Classics are another group that reuses ISBN's.  I've ordered some for our school English program and there's no way to tell if the book I will receive was printed 20 years ago or last month...same ISBN so no wrongdoing on senders part.  For this use, I'd like newer editions b/c they tend to hold up longer to multiple uses.  With the ISBN's in use for extended periods tho, I've stopped ordering some books this way and instead opt for UBS where I can actually see the condition/age.

you make a good point Denise.......my daughter is in her second year of teaching HS and 8th grade honors English and didn't realize books with the same ISBN can have different covers too.

Actually, most recent travel books by the big travel publishers  have different ISBNs for the different editions. I buy a lot of travel books and i havent had an ISBN issue except for books more than 10 years old. If you look on Amazon and the 2nd and 1st edition have different ISBNs, you can try for the title change in the listing. Make a note of it in the notes area so the BDE team will go research it. 

I agree with with Sianeka's comments.

Travel books are frequently updated by publishers to reflect new and timely information, and most people who are looking for travel books are not interested in older editions, say from 1986 or the 1990's. If you want a specific edition or a copy of the book no older that a given date, then you need to specify that in an RC when requesting it.