Div content scrolls on mouse move on a dropdown me

Question

I have div with multiple dropdown menus in it. With the menu open (let say 3rd one) if I move mouse over the menu towards bottom, the whole div content starts scrolling down. Here is the example

http://jsfiddle.net/M3MhW/7/

 <ul class="actionMenu" id="centralObjUL" >
   <li class="actionMenuLi" id="liAction" onclick="displaySubMenu(this)" >
      <a class="actionMenuLink" onkeydown="keydown('','Link1')" onblur="liOnblur(this.parentNode)" href="javascript:void(0);">Actions&nbsp;&nbsp;&nbsp;</a>
      <ul class="actionSubMenu" id="subMenu" style="display: none;">
         <li class="actionSubMenuLi">
            <a class="actionSubMenuLink" id="Link1"  onmousemove="fnMenuMouseMove(this)" onkeydown="keydown('Link1','Link2')" onfocus="aOnfocus(this,'subMenu')" onblur="aOnblur(this,'liAction')" href="javascript:void(0);">Client link 1</a>
         </li>
         <li class="actionSubMenuLi">
            <a class="actionSubMenuLink" id="Link2"  onmousemove="fnMenuMouseMove(this)" onkeydown="keydown('Link1','Link3')" onfocus="aOnfocus(this,'subMenu')" onblur="aOnblur(this,'liAction')" href="javascript:void(0);">Client link 2</a>
         </li>
         <li class="actionSubMenuLi">
            <a class="actionSubMenuLink" id="Link3"  onmousemove="fnMenuMouseMove(this)" onkeydown="keydown('Link2','Link4')"  onfocus="aOnfocus(this,'subMenu')" onblur="aOnblur(this,'liAction')" href="javascript:void(0);">Client link 3</a>
         </li>
         <li class="actionSubMenuLi">
            <a class="actionSubMenuLink" id="Link4"  onmousemove="fnMenuMouseMove(this)" onkeydown="keydown('Link3','PRFS')"  onfocus="aOnfocus(this,'subMenu')" onblur="aOnblur(this,'liAction')" href="javascript:void(0);">Client link 4</a>
         </li>
      </ul>
   </li>
</ul>