This may sound strange, but I have an AJAX script that works in many browsers and many computers (IE 6 & 7, FF, Safari, both Win and Mac), but won't work in either Safari or Firefox on a Mac with Leopard.

Basically I am using form with drop down menus that populate dynamically upon selection of each item, and then submits and updates the div below it with the text.

I tried using Firebug, and it seems to refresh the whole page (instead of submitting the form through AJAX), so I can't catch the error. In Safari, I used the Develop Menu and get this error anytime I want to make an ajax call (although all of the other calls work): "Refused to set unsafe header Content"

Does anyone know about this? Or could it just be a bug in my code?