Do you think it could be this?
Code:
<p style="margin-top: -1px; color: rgb(51, 102, 204);"><font size="1">If you use one of the proprietary
I don't think zen cart put that there, by the way that's pink, not red.
Edit: Sorry, this is where the problem starts:
Code:
<font color="#ff3366"><strong><p style="margin-top: -1px; color: rgb(255, 51, 0);"><font color="#cc0000">
Your HTML is a complete mess, I suggest you stop using whatever WYSIWYG editor you're using and look at the source yourself. The problem is that you have unclosed font tags and all the browsers have different preferences on which one is more important, Firefox simply obeys the first one.