I recently reinstalled my operating system, and reinstalled Mozilla Firefox. For all practical purposes, my configuration is exactly what it was two days ago.<p>However, now I've noticed that margins are a few pixels off in FF3. I'm concerned about designing on this box now, as my CSS might be a few pixels off.<p>I'm wondering, what might be the cause of this discrepancy?
I really doubt its the margins.<p>What kind of fonts are on the page? I bet the problem is that you don't have Microsoft fonts installed. (they're not included with Linux distros, for example)
You need to provide more info: what is your O/S, what is your baseline (markup and stylesheet developed/tested first in FF/firebug/Safari vs. IE 6 or 7?), whether your sure this is not an IE 6/7 "feature".