How can I stop ASP.NET Menu controls from generating inline html style elements

<style type="text/css">
    .ctl00_SiteHeader1_TabBar1_Menu1_0 { background-color:white;visibility:hidden;display:none;position:absolute;left:0px;top:0px; }
    .ctl00_SiteHeader1_TabBar1_Menu1_1 { text-decoration:none; }
    .ctl00_SiteHeader1_TabBar1_Menu1_2 {  }
    .ctl00_LeftColumnContent_LeftHandNavigator1_Menu1_0 { text-decoration:none; }

</style>
</head>

<body>