[OS X TeX] ``/usr/texbin/pdflatex´´ does not exist

[Charlse Darwin]

I'm trying to open a .tex file and TexShop gives me the following  
error message:

/usr/texbin/pdflatex does not exist. Perhaps TeXLive was not  
installed or was removed during a system upgrade. If so, go to the  
TeXShop web site and follow the instructions to (re)install TeXLive.  
Another possibility is that a tool path is incorrectly configured in  
TeXShop preferences. This can happen if you are using the fink teTeX  
distribution.

I do have pdflatex installed however:

$ which pdflatex
/opt/local/bin/pdflatex

I tried setting up the path in Preferences but had no luck. For `(pdf) 
TeX´, I changed /usr/texbin to ``/usr/texbin:/opt/local/bin´´ and  
once that's didn't work, for `Distiller´, I changed /usr/local/bin to  
``/usr/local/bin:/opt/local/bin´´, again nothing.

Your thoughts please?