You will have to edit the CSS of the template and change mainlevelmainnav to mainmenu in that code because your module uses a different ID:
.moduletablemainnav { /* I have absolutely positioned the module, you might have a different scheme. */
float:left;
z-index:100;
font:0.9em Verdana, Arial, Helvetica, sans-serif;
margin:0;
padding:0;
}
#mainlevelmainnav ul {
float:left;
list-style:none;
line-height:1em;
margin:0;
padding:0;
background-color:#000;
}
#mainlevelmainnav li {
float:left;
background-image: url(../images/parenthese.jpg);
background-repeat: no-repeat;
background-position: right;
padding-right:28px;
margin-top:6px;
font-weight:bold;
font-size:12px;
}
#mainlevelmainnav a {
display:block;
text-decoration:none;
margin-left:25px;
color:#FFF;
}
#mainlevelmainnav a:hover {
color:#14cbec;
}
#mainlevelmainnav a.sublevelmainnav {
font-weight:normal;
padding-bottom:5px;}
a#active_menumainnav{
color:#14cbec;}
#mainlevelmainnav li ul {
position:absolute;
left:-999em;
margin:0;
padding-bottom:10px;
padding-top:10px;
}
#mainlevelmainnav li li {
float:none;
background:none;
}
#mainlevelmainnav li:hover ul,#mainlevelmainnav li li:hover ul,#mainlevelmainnav li li li:hover ul,#mainlevelmainnav li.sfhover
ul,#mainlevelmainnav li li.sfhover ul,#mainlevelmainnav li li li.sfhover ul {
left:auto;
z-index:6000;
}
#mainmenu{
height:30px;
background-color:#000;
}
a.mainlevelmainnav{
padding-bottom:3px;}