title: rgba not working in IE9
body: <p>For some reason, I can't get rgba working within my CSS using IE9. I've tested it using Chrome, and it works fine. Not sure what's wrong.</p>
  
  <p>My HTML is:</p>
  
  <pre><code>&lt;!doctype html&gt;
  
  &lt;html lang="en"&gt;
      &lt;head&gt;
          &lt;meta charset="utf-8" /&gt;
  
          &lt;title&gt;&lt;?php bloginfo('name'); ?&gt; - &lt;?php bloginfo('description'); ?&gt;&lt;/title&gt;
  
          &lt;link href="&lt;?php bloginfo('stylesheet_url'); ?&gt;" rel="stylesheet" type="text/css" /&gt;
          &lt;link href="http://fonts.googleapis.com/css?family=Raleway:100&amp;v1" rel="stylesheet" type="text/css" /&gt;
  
          &lt;script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.6.1/jquery.min.js"&gt;&lt;/script&gt;
      &lt;/head&gt;
      &lt;body&gt;
          &lt;?php wp_nav_menu(); ?&gt;
      &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>My CSS is:</p>
  
  <pre><code>body,div,dl,dt,dd,ul,ol,li,h1,h2,h3,h4,h5,h6,pre,code,form,fieldset,legend,input,textarea,p,blockquote,th,td{margin:0;padding:0;}table{border-collapse:collapse;border-spacing:0;}fieldset,img{border:0;}address,caption,cite,code,dfn,em,strong,th,var{font-style:normal;font-weight:normal;}li{list-style:none;}caption,th{text-align:left;}h1,h2,h3,h4,h5,h6{font-size:100%;font-weight:normal;}q:before,q:after{content:'';}abbr,acronym{border:0;font-variant:normal;}sup{vertical-align:text-top;}sub{vertical-align:text-bottom;}input,textarea,select{font-family:inherit;font-size:inherit;font-weight:inherit;}input,textarea,select{*font-size:100%;}legend{color:#000;}
  
  body {
      font-size: 62.5%;
  }
  
  .menu {
      font-size: 5em;
      font-family: 'Raleway', arial, serif;
  }
  
  .menu ul li a {
      background: rgba(0,0,0,0.5);
      text-decoration: none;
  }
  </code></pre>