Media Queries überschreiben nicht native-Formate?

Frage ich mich, warum einige meiner media queries überschreiben nicht die native Stile in der view-port Ihres seins genannt. Ich bin versucht zu restyle ein Menü dementsprechend, zu stapeln, und die Navigations-Bereich ist die Höhe, mehr in ein WP-theme. Aber jeder, welchen Weg ich die specs, die ich anlegen um diesen Effekt zu bekommen über die Bearbeitung der Live-CSS in Safari oder FF, element untersuchen - die Stile, die ich einfügen unter bestimmten viewport ich bin targeting nicht gelesen. Ich weiß, ich bin mit media queries korrekt, wie es liest NEUE Stile, nur nicht überschreiben native? Ich bin hier etwas fehlt? Hier ist, was ich bin versucht hinzuzufügen, dass nicht gelesen wird.

@media only screen and (min-device-width: 320px) and (max-device-width: 480px) {

#access li {
    float: none; //To translate to not to float to the left stack
    position: relative;
}

#access {
    background: url("http://testsite.com/wp-content/uploads/2012/01/menu_bg.gif") repeat scroll 0 0 transparent;
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.4);
    clear: both;
    display: block;
    float: left;
    height: 240px; //Changed the height to allow stack
    width: 100%;
}

Edit: Hier ist die VOLL set von Responsive Stile, die ich rufe, wenn Angelegenheiten.

  /* =Responsive Structure
----------------------------------------------- */

@media (max-width: 800px) {
    body {
        padding: 0;
    }
    #page {
        margin-top: 0; overflow: hidden;
    }
    #branding {
        border-top: none;
    }
        #signup { display:none; }
        #adbox { display:none; }
        #adbox2 { display:none; }
        #socialpost { margin-left: -100px; }
        p {font-size: 12px; }
        #sublogo { display: none; }
        #footcontain {  padding-left: 0;}

        #access a {
        color: #000000;
        display: block;
        font-family: arial;
        line-height: 3.11em;
        padding: 0 20px;
        text-decoration: none;
        #access a { font-size: 12px; }

        #access li {
        float: left;
        margin-left: -28px;
        position: relative; }
}

@media (max-width: 650px) {
    /* @media (max-width: 650px) Reduce font-sizes for better readability on smaller devices */
    body {
        padding: 0;
    }
    #page {
        margin-top: 0;
    }
    #branding {
        border-top: none;
    }
        #signup { display:none; }
        #adbox { display:none; }
        #adbox2 { display:none; }
        p {font-size: 12px; }
        #sublogo { display: none; }

        #access a {
         color: #000000;
         display: block;
         font-family: arial;
         line-height: 3.11em;
         padding: 0 13px;
         text-decoration: none;
         font-size: 11px;}
         #footcontain {  padding-left: 0;}
         #access a {
         padding: 0 15px; }

}

@media (max-width: 450px) {
        #content .gallery-columns-2 .gallery-item {
    width: 45%;
    padding-right: 4%;
    }
    #content .gallery-columns-2 .gallery-item img {
        width: 100%;
        height: auto;
    }
        #signup { display:none; }
        #adbox { display:none; }
        #adbox2 { display:none; }
        p {font-size: 10px; }

       .entry-content, .entry-summary {
        padding: 1.625em 0 0;
        width: 48%; }
        #footcontain {  padding-left: 0;}

        #branding #s {
       -moz-transition-duration: 400ms;
       -moz-transition-property: width, background;
       -moz-transition-timing-function: ease;
        float: right;
        height: 35px;
        width: 47px; }

        .widget-title { margin-top: 35px; }

        .flexslider .slides img {
         border: 0 none;
         display: block;
         max-width: 100%;
         padding-bottom: 25px; }
         #footcontain {  display:none;}

         #access li {
         float: none;
         position: relative;
         }

         #access {
         height: 70px;
         }

         #access a {
         color: #000000;
         display: block;
         font-family: arial;
         font-weight: bolder;
         line-height: 3.11em;
         padding: 0 10px;
         text-decoration: none;
         }

         #access ul {
         font-size: 10px;
         list-style: none outside none;
         margin: 0 0 0 -80px;
         padding-left: 0;
         }

        .flex-control-nav { display: none; }
        .flexslider {
         margin: 0 0 67px; }
        .flex-caption {  display: none; } //Could Display this here, need to make take half of slider

}

@media only screen and (min-device-width: 320px) and (max-device-width: 480px) {
    body { padding: 0; }

        #access {
        height: 70px;
        }

    #page {
        margin-top: 0; overflow: hidden;
    }
    #branding {
        border-top: none;
    }
        #signup { display:none; }
        #adbox { display:none; }
        #adbox2 { display:none; }
        p {font-size: 10px; }
        #sublogo { display: none; }
        #access a { padding: 0 10px; }

        #access li {
        float: none;
        position: relative;
        }

       .entry-content, .entry-summary {
        padding: 1.625em 0 0;
        width: 35%; }
        #footcontain {  display: none; }

       #branding #s {
         -moz-transition-duration: 400ms;
         -moz-transition-property: width, background;
         -moz-transition-timing-function: ease;
         float: right;
         height: 35px;
         width: 47px; }

        #footcontain { display: none; }

        .widget-title { margin-top: 35px; } //Attempt to Create Space for Slider Page Nation
        #access { height: 70px; }

        #access li {
        float: none;
        position: relative;
        }

       .flex-control-nav { display: none; }

       .flex-caption {  display: none; } //Could Display this here, need to make take half of slider, check 
       .flexslider {
       margin: 0 0 67px; }

}