Well, I may have successfully answered my own question.
Within the file, , there's a snippet of code listed under the "//browsers" section that determines the browser version:
elseif( strstr($ua, 'firefox/3.5') ) $b[] = $g . ' ff3 ff3_5';
elseif( strstr($ua, 'firefox/3') $b[] = $g . ' ff3';
elseif( strstr($ua, 'firefox/3') $b[] = $g . ' ff4';
elseif( strstr($ua, 'firefox/3') $b[] = $g . ' ff5';
To this, I simply added:
elseif( strstr($ua, 'firefox/10') $b[] = $g . ' ff10';
at the end of that list. The final view within the code is this:
elseif( strstr($ua, 'firefox/3.5') ) $b[] = $g . ' ff3 ff3_5';
elseif( strstr($ua, 'firefox/3') $b[] = $g . ' ff3';
elseif( strstr($ua, 'firefox/3') $b[] = $g . ' ff4';
elseif( strstr($ua, 'firefox/3') $b[] = $g . ' ff5';
elseif( strstr($ua, 'firefox/10') $b[] = $g . ' ff10';
I've tested it with Firefox 10 and it seems to work fine.
Hope this helps someone else!