Java Applet overlapping menu on Chrome

In Brief: The Java Applet overlaps menu on Chrome (version 30.0), but in Firefox it works correctly. I've checked out several forums, but nothing seems to work for me.


In Detail:
When I hover over the drop-down-menu, it goes behind the java applet. I've assigned z-index to my drop-down menu and renders the menu over all content in the frameset, but the Java Applet.

Following is the frameset structure for that particular page. Any help is deeply appreciated.

<div id="drop-down-menu"><ul> ... </ul></div>

<iframe id="frame1">
  <frameset rows="50,*,30">
    <frame src="top_menu.jsp" id="frame2">
    <frameset cols="35,*">
      <frame src="tree_navigation.jsp" id="frame4">
      <frameset cols="20,*,0,0>
        <frame src="toolbar.jsp" id="frame5">
        <frame src="welcome.jsp" id="frame6">
        <frame src="java_applet.jsp" id="frame7">
        <frame src="other.jsp" id="frame8">
      </frameset>
    </frameset>
    <frame src="footer.jsp" id="frame3">
  </frameset>
</iframe>

Select allOpen in new window