Ack! Spanish Editions

[Amber]

Hey guys, 

So I have a friend who travels like mad and brings me back an HP book 
every time she leaves the country.  A couple of weeks ago she brought 
me back a copy from Mexico.  Yeah!!!!  

Then last week or so I was reading an article about the translation 
for the 5th book in Spanish and it said something about the different 
translations it does, i.e. Catalan, Galician, Castillian, and it said 
that Salamandra (Castillian) has different regional versions for S. 
America, US, Spain, and Mexico.  That got me thinking.

At my bookstore, we have the spanish version that looks EXACTLY like 
the one my friend brought back, but has a different ISBN (like the 
social security number for books).  I bought that book too and 
started flipping through to random pages and comparing them.  They 
are the same! 

So, being a library person I went to my top sources (my mom and my 
boss) who work in libraries and asked them.  They appear to have 
different distributors, but I don't see why they would have different 
isbns!  They are both trade size paperbacks.  They look exactly the 
same.

Does anyone out there in HP land know why this is so?  Or did I just 
spend $15.00 on a duplicate book?


Desparately Seeking answers,

Amber