title: Double-drop down weird behaviour
body: <p>Site: <a href="http://oppcess.test-lca-website.com/" rel="nofollow">http://oppcess.test-lca-website.com/</a></p>
  
  <p>I've been noticing an odd behaviour that is rather bizarre. I have a WordPress site and have created a horizontal sub-menu.  It works fine but the strangest thing happens.  If you move the mouse over the About button, the sub-menu drops but what gets strange is thatwhen you get to about 1/10th" of an inch away from the right-edge of the button, the dropdown suddenly changes to a vertical drop-down.  Even stranger, this ONLY happen when you move from left to right, I can't get it to do the same of I move from right to left.</p>
  
  <p>This is the CSS I'm using for the sub-menu:</p>
  
  <pre><code>.block-type-navigation li:hover ul.sub-menu li {
      display: block !important; 
      float: left;
      width: 25% !important;
  }
  
  .block-type-navigation ul.sub-menu li a {
      min-width:100px;
  }
  </code></pre>
  
  <p>Which does seem to work just fine.  I'm quite baffled by this seemingly '1 pixel' spot that shows the vertical menu.</p>