Centralização de menu não funcionando

Qual é minha questão:
Bom, faço de tudo, mas meu menu não fica centralizado.
Algum código para resolver? Problema: https://i.imgur.com/5i6kY.jpg

Endereço do meu fórum:
http://tech.forum-pro.net

Versão do fórum:
PHPBB3

Poderia me mandar seu css , ?

Painel de controle Visualização Página inicial ou home page Cabeçalho e navegação.

Posição do menu : Centralizar

"Mafioso", não funciona isto.

Meu CSS abaixo.

Código:

/* Barra copyright */
#page-footer a{
color:#939393;
}

/* Módulo novidades */
.mod_news .row3 {
text-align: right;
}

/* Fundo dos widgets, anúncios, categorias, fóruns */
.introduction .inner {
background: #282828 url('http://i76.servimg.com/u/f76/11/66/91/15/c_left12.png') no-repeat top left;
padding: 0px 0px 0px 15px;
min-height: 130px;
}
.introduction {
background: url('http://i76.servimg.com/u/f76/11/66/91/15/c_righ10.png') no-repeat top right;
padding: 0px 15px 0px 0px;
margin-bottom: 20px;
}
#fa_ticker_block .module .inner {
background: #282828 url('http://i76.servimg.com/u/f76/11/66/91/15/c_left12.png') no-repeat top left;
padding: 0px 0px 0px 15px;
min-height: 130px;
}
#fa_ticker_block .module {
background: url('http://i76.servimg.com/u/f76/11/66/91/15/c_righ10.png') no-repeat top right;
padding: 0px 15px 0px 0px;
margin-bottom: 20px;
}
.forabg .inner {
background: #282828 url('http://i76.servimg.com/u/f76/11/66/91/15/c_left12.png') no-repeat top left;
padding: 5px 0px 0px 15px;
min-height: 130px;
}
.forabg {
background: url('http://i76.servimg.com/u/f76/11/66/91/15/c_righ10.png') no-repeat top right;
padding: 0px 15px 0px 0px;
}
.forumbg .inner {
background: #282828 url('http://i76.servimg.com/u/f76/11/66/91/15/c_left12.png') no-repeat top left;
padding: 5px 0px 0px 15px;
min-height: 130px;
}
.forumbg {
background: url('http://i76.servimg.com/u/f76/11/66/91/15/c_righ10.png') no-repeat top right;
padding: 0px 15px 0px 0px;
}
.portal .module .inner, #left .module .inner, #right .module .inner {
background: #282828 url('http://i76.servimg.com/u/f76/11/66/91/15/c_left12.png') no-repeat top left;
padding: 0px 0px 0px 15px;
min-height: 130px;
}
.portal .module, #left .module, #right .module {
background: url('http://i76.servimg.com/u/f76/11/66/91/15/c_righ10.png') no-repeat top right;
padding: 0px 15px 0px 0px;
margin-bottom: 20px;
}

/* Caixa de pesquisa*/
input.search {
background-image: url('http://i76.servimg.com/u/f76/11/66/91/15/search10.png');
background-repeat: no-repeat;
background-position: left 1px;
padding-left: 17px;
}

/* Menu mensagens privadas */
ul#privmsgs-menu li {
font-size: 14px;
margin: 0px 5px 0px 5px;
padding: 5px 0px 5px 5px;
}
ul#privmsgs-menu li img {
display: none;
}
ul#privmsgs-menu li+li{
border-left: 1px solid #424242;
}
ul#privmsgs-menu {
padding: 15px 0px;
}

/* Cabeçalho e menu de navegação */
#page-header .headerbar {
background: url('http://i76.servimg.com/u/f76/11/66/91/15/header10.gif')repeat-x bottom left;
margin-bottom: 0px;
}
#page-header {
margin: -5px;
}
#page-header .navbar {
background: url('http://i76.servimg.com/u/f76/11/66/91/15/body_b10.gif')repeat-x top left;
padding: 10px;
}
#page-header .navbar ul.navlinks {
border-bottom: 0px;
font-weight: normal;
}
#i_icon_mini_index, #i_icon_mini_faq, #i_icon_mini_search, #i_icon_mini_members, #i_icon_mini_groups, #i_icon_mini_profile, #i_icon_mini_register, #i_icon_mini_message, #i_icon_mini_logout, #i_icon_mini_calendar, #i_icon_mini_portal, #i_icon_mini_login, #i_icon_mini_gallery, #i_whosonline {
display: none;
}
#page-header .navbar ul {
margin: 0 10px 0 0px;
padding: 0px 0px 0px 0px;
list-style-type: none;
}
#page-header .navbar ul li {
margin: 0;
padding: 0;
list-style: none;
float: left;
}
#page-header .navbar ul li a {
color: #939393;
display: block;
padding: 22px 12px 22px 12px;
text-decoration: none;
}
#page-header .navbar ul li a:hover {
color: #ffffff;
}
* html #page-header .navbar ul li a {
display: inline-block;
}
* html #page-header .navbar {
height: 1%;
}
#page-header .navbar .navlinks {
font-size: 0px;
border-bottom: 0px;
}
#page-header .navbar .navlinks a {
font-size: 14px;
font-family: arial;
}
#page-header .navbar span.corners-bottom {
display: none;
}
#page-header .navbar span.corners-top {
display: none;
}
#search_menu {
font-size: 11px;
}
.overview {
border: 0px;
}
.title-overview {
background: url('http://i76.servimg.com/u/f76/11/66/91/15/header10.gif')repeat-x bottom left;
color: #FFFFFF;
}
#search_menu p+p {
background: url('http://i76.servimg.com/u/f76/11/66/91/15/body_b10.gif')repeat-x top left;
color: #FFFFFF;
}
.center-overview{
color: #FFFFFF;
}
.navbar .row3{
background: url('http://i76.servimg.com/u/f76/11/66/91/15/body_b10.gif')repeat-x top left;
}
.center-overview label {
color: #FFFFFF;
}
#search_menu p {
margin-bottom: 0px;
padding-bottom: 0.5em;
}
#search_menu hr.dashed {
border: 0px;
margin: 0px;
}
#search_menu .center-overview a { 
padding: 0px !important;
background: none !important;
text-shadow: 0px transparent !important;
}
.center-overview .inputbox {
background-color: #282828;
border: 1px solid #424242;
}
.center-overview input.button1 {
background: #282828;
border: 0px;
padding: 5px;
color: #424242;
border: 1px solid #424242;
}
#page-header #search-box {
display: none;
}

/* Página de edição e exibição de perfil */
#cp-main span.corners-top, #cp-main span.corners-top span, #cp-main span.corners-bottom, #cp-main span.corners-bottom span {
background-image: none;
}
#profile-tab-field-profil div.separator{
border-bottom: 1px solid #424242;
}

/* Largura fórum */
#wrap {
width: 975px;
}

/* Widgets portal */
.portal .module .h3, #left .module .h3, #right .module .h3 {
color: #dadada;
border-bottom-color: #424242;
text-align: center;
text-transform: capitalize;
font: 14px arial;
margin-bottom: 8px;
margin-top: 3px;
padding: 8px 0px;
}
.portal .module span.corners-top {
background-image: none;
margin: 0px;
}
.portal .module span.corners-top span {
background: url('http://i76.servimg.com/u/f76/11/66/91/15/center10.png') repeat-x top center;
height: 15px;
}
.portal .module span.corners-bottom {
background-image: none;
}
.portal .module span.corners-bottom span {
background-image: none;
}

/* Retirar cantos arredondados */
span.corners-top, span.corners-top span, span.corners-bottom, span.corners-bottom span {
background-image: none;
}

/* Caixa de selecção */
select {
background: #282828;
color: #dbdbdb;
border-color: #424242;
}

/* Área de mensagem */
.post {
background: #262626 url('http://i76.servimg.com/u/f76/11/66/91/15/header10.gif') repeat-x bottom left;
}

/* Texto barra fóruns e categorias */
.forabg ul.topiclist li.header dd, .forabg ul.topiclist li.header dt {
padding: 5px 0px;
text-transform: capitalize;
color: #939393;
}
.forumbg ul.topiclist li.header dd, .forumbg ul.topiclist li.header dt {
padding: 5px 0px;
text-transform: capitalize;
color: #939393;
}

/* Botões caixa de texto */
#format-buttons .button2{
background: #cccccc;
border: 1px solid #424242;
}

/* Botões */
.inputbox {
background-color: #282828;
border: 1px solid #424242;
}
a.button1, input.button1, a.button2, input.button2, button.button2 {
background: #282828;
border: 0px;
padding: 5px;
color: #939393;
border: 1px solid #424242;
}

/* Links sem linha focus */
a {
outline: none;
}
dd.lastpost {
margin-left: 9px !important;
}
#divbold, #divcolor, #divitalic, #divsmilies, #divstrike, #divunderline, #main-content a.cgu-buttons, #message, .spoiler dt, button.button2, input#submit_button, input.button1, input.button2, input.liteoption, input.mainoption {
-moz-border-radius: 3px;
-webkit-border-radius: 3px;
background: #F4F5F4 url(http://i66.servimg.com/u/f66/11/96/49/61/tabbg10.png);
border: solid 1px #DDD;
border-radius: 3px;
padding: 2px;
}
a.mainmenu{
position: center;
}


ponha esse

Código:

 a.mainmenu{
position: center;
}