why does a dropdown combobox list (select html tag) disappear very quickly in IE 7 but works fine in firefox

i have 开发者_开发技巧a combobox and its on a narrow part of a webpage. below is my dropdown html.

THe issue is that in IE 7 only (works fine in firefox) after i click on the dropdown, the list of items pops up and i go to click on an item in the list and it disappears before i get a chance to click.

It seems to work fine in IE8 as well but in IE7 (most of my users) no one has time to click before the list disappears.

      <select id="staticData">
          <option value="">(Please select)</option>
             <optgroup label="Geographical">
                <option value="B">United states of AMerica</option>
                <option value="C">Europe</option>
                <option value="D">Asia</option>
             </optgroup>
             <optgroup label="Related">
                 <option value="RoadmapItem">Roadmap items</option>
             </optgroup>
     </select>

This fixed it.

http://css-tricks.com/select-cuts-off-options-in-ie-fix/