Menu alignment.. Desperately need help!!!

I inherited this template (NOT A TM template for those who are wondering..:laugh:), and I don't have much choice about changing it.. I just need to make this work. Hoping the community can help.. Here's the site: **http: // clients . overthehillweb . com/ progroom /
**
The menu right underneath the logo is driving me nuts.. I cannot get those darn tabs to flush to the left to save me, and I can't make sense of this bloody stylesheet to figure out how the heck to do this..

I hope one of our resident CSS gurus can help me untangle this mystery.. PLEASE!!!:smile:

#top_nav {
    background: #3a88a9 url("../images/ezpages_bg.gif");
    font-family: verdana, arial, helvetica, sans-serif;
    font-size: 1.15em;
    margin: 0em;
/*    padding: 0.5em;*/
    height: 39px;
    }

#tab_nav a {
    color: #ffffff;
    text-decoration: none;
}

#tab_nav li {
    float: left;
    background: url("../images/bg_tabs_left.gif") no-repeat 0 0;
    padding: 0 0 0 5px;
    border-right: 1px solid #3a88a9;
}

#tab_nav li a {
    display: block;
    background: url("../images/bg_tabs_right.gif") no-repeat right 0;
    padding: 10px 20px 10px 18px;
}

#tab_nav li:hover {
    background-position: left -40px;
}

#tab_nav li:hover a {
    background-position: right -40px;
}

#tab_nav #tab_active{
    background-position: 0 -78px;
}

#tab_nav #tab_active a {
    background-position: right -78px;
}

#tab_nav li.home-link {
    padding: 0;
}

#tab_nav li.home-link a {
    display: block;
    background: url("../images/home_tab.gif") no-repeat left 0;
    padding: 0px 20px 10px 18px;
    height: 27px;
    width: 2px;
}

#tab_nav li.home-link:hover a {
    background-position: left -39px;
}


#login_logout_section, #login_logout_section a {
    font: normal 11px verdana, arial;
    color: #ffffff;
    padding: 11px 7px;
}
#login_logout_section a:hover {
    text-decoration: none;
}

.top-nav-right {
    background: url("../images/top_nav_right_bg.gif") right top;
    height: 39px;
    width: 6px;
    float: right;
}

.top-nav-left {
    background: url("../images/top_nav_left_bg.gif") left top;
    height: 39px;
    width: 6px;
    float: left;
}