When I worked with smarty template debug mode, these variables are checked to be assigned in {$mod_config}.
top_message => "<h1 class="d3f_title">..."
show_breadcrumbs => 1
default_options => "smiley,xcode,number_entity,html"
allow_html => 1
allow_textimg => 0
allow_sig => 1
allow_sigimg => 0
posts_per_topic => 100
hot_threshold => 10
topics_per_page => 20
use_vote => 1
use_solved => 1
allow_mark => 1
allow_hideuid => 0
viewallbreak => 10
selfeditlimit => 31536000
selfdellimit => 0
css_uri => "{mod_url}/index.php?page=main_css"
images_dir => "images"
body_editor => "common_fckeditor"
anonymous_name => "Guest"
guest_vote_interval => 86400
antispam_groups => Array (1)
0 => ""
antispam_class => "default"
notification_enabled => 0
Do you have any ideas?