It seems to me the current behavior of Mathematica wrt to how it handles 
this matter is not logical.
Consider this:
I opened notebook folderA/a.nb, then opened another notebook 
fodlerB/b.nb. So now have 2 notebooks open.
Did some editing to a.nb, then did File->Save
Where do you expect a.nb to saved to?  folderA ofcourse ! but no, 
Mathematica saves a.nb to folderB ! because that was the the folder I 
opened a notebook from last.
Does this make any sense?  Should'nt the notebook be saved to the same 
place it was opened from?  This can cause one to lose changes made, and 
it happend to me. Becuase I did not notice the notebook was saved to a 
different folder, and next time I started a new session, and opened 
a.nb, the changes I made were not there.
Is there an option to have Mathematica change this behavior to the 
logical behavior of saving the notebook to the same folder it was opened 
from unless otherwise told to?
Right now, each time I want to save a notebook, I have to do File->SAVE 
AS, and navigate to the orginal folder the notebook lives in and have to 
keep answering the question asking me if I am sure I want to overwrite 
the notebook, which is scary sometimes.
I am sure someone will try to explain to me that this current behavior 
is completely logical and all that, but for me, it completely makes no 
sense at all.
ps. I looked at preferences, and do not see anything there to change this.
Thanks,
--Nasser
This is not what I get. A notebook that already exists is always saved 
to its original location. A new notebook will give a save popup that is 
in the folder most recently used to save a nb, but you can navigate to 
wherever you want.
Kevin