xpi for the mac...

I have written an add-in to mozilla and have tested in on windows.  I 
know want to see if it works on the mac.  I adjusted the install script 
so that in installs on a mac (looking at how multizilla does their 
install for a mac).  When I get it installed and run mozilla, I am 
getting errors though.  This add-in adds one jar file and replaces some 
jar files and I noticed when I look at the package contents that these 
files are saved as .jar files but their kind is of text file and mozilla 
has its jar files as kind document.  The jar file I added is saved as 
kind document though.  Does anyone know why this is happening and how to 
correct it?  I was under the assupmtion that if I had something that 
worked on windows mozilla, the only thing I would need to change to get 
it to work on a mac mozilla was to change the install...is that an 
incorrect assumption?  Thanks.