[cflsystems]

You will not find this no matter what you do and there is no setting in admin... suprise, it is hard coded of course - in include/func/func.image.php - function func_ic_get_size_catthumbn

The strange thing about it though is that the function accepts width and height as parameters but they are not used anywhere in the function body - they are hardcoded instead

function func_ic_get_size_catthumbn($width, $height, $skin_name = '')
{
    global $alt_skin_info;
    if (empty($skin_name))
        $skin_name = $alt_skin_info['alt_schemes_skin_name'];
    // Get thumb_dims for schemes bt:88678 bt:93891 bt:121806
    $icon_sizes["books_and_magazines"] = $icon_sizes['ideal_comfort'] = $icon_sizes['2-columns'] = $icon_sizes['3-columns'] =   $icon_sizes['fashion_mosaic_blue'] = $icon_sizes['fashion_mosaic_green'] = $icon_sizes['fashion_mosaic_grey'] = $icon_sizes['fashion_mosaic_pink'] = $icon_sizes['vivid_dreams_aquamarine'] = $icon_sizes['vivid_dreams_violet'] = array('width' => '16', 'height' => '16');
    $icon_sizes["vivid_dreams_chromo"] = array('width' => '32', 'height' => '32');
    $icon_sizes["vivid_dreams_lotus"]  = array('width' => '32', 'height' => '32');
 
    if (isset($icon_sizes[$skin_name])) {
        $result = $icon_sizes[$skin_name];
    } else {
        $result = array('width' => '24', 'height' => '24'); //Default value for 3rd party skins.
    }
    return $result;
}

This is just one of the things you will not find any logic behind....