Firefox中的错误？表格在Chrome / IE＆amp;火狐

Question

以下JS Fieddle显示IE和E的预期输出Chrome，但在Firefox中，它完全不同。

什么问题？

http://jsfiddle.net/webtiki/kQXkt/7/

table {
    width:90%;
}
td {
    width:30%;
    position:relative;
}
td .dummy{
    margin-top:100%;
}
td .content {
    position:absolute;
    top:0;
    bottom:0;
    left:0;
    right:0;
    background:gold;
}


<table>
    <tr>
        <td>
            <div class="dummy"></div>
            <div class="content">1</div>
        </td>
        <td>
            <div class="dummy"></div>
            <div class="content">1</div>
        </td>
        <td>
            <div class="dummy"></div>
            <div class="content">1</div>
        </td>
    </tr>
    <tr>
        <td>
            <div class="dummy"></div>
            <div class="content">1</div>
        </td>
        <td>
            <div class="dummy"></div>
            <div class="content">1</div>
        </td>
        <td>
            <div class="dummy"></div>
            <div class="content">1</div>
        </td>
    </tr>
    <tr>
        <td>
            <div class="dummy"></div>
            <div class="content">1</div>
        </td>
        <td>
            <div class="dummy"></div>
            <div class="content">1</div>
        </td>
        <td>
            <div class="dummy"></div>
            <div class="content">1</div>
        </td>
    </tr>
    <table>