I have no idea at all, first of all, of image internal composition and color modes.
That said, I have a very strange problem.
These are the pictures:
Well, the ORIGINAL is more colorful in Firefox, but the second is like powered off (I dont know english word for that). It looks like the yellow-orange at the left center is changed.
I needed to slow the size from 1mb to about 300k, so I opened the original with Fireworks and Photoshop (ps is the second link) with the same results.
This is not a life matter, I am just curious why this happens.
If you go to http://tracker.fusiondev.com.ar and look at
wrapper div with
Firebug u will be able to change the background URL to the original.jpg and see what I am talking about.
EDIT: If you open both URLs in Firefox u will see the change inmediatly.