[kh99]

You could try:

      .
      .
    $class = ($c % 2 == 0 ? 'alt2' : 'alt1'); 
    eval('$categorybits .= "<tr>\n<td class=\"$class\" width="33%"> <span class=\"smallfont\">' . ($group['limit'] ? '(Top $group[limit] by $order)' : '') . '</span><div style=\"margin-left: 0.5%\">";'); 
      .
      .

(adding the part in red) but I'm not sure. Also, it looks like the code is set up to allow a variable number of columns, and this of course assumes 3. (It would be easy enough to use the number of categories and put in code to calulate the percentage for equal width columns, but at least see if it works at all first).