Scroll issues with / CakePHP autocomplete result list

Using the Ajax helper for CakePHP (currently to provide an $ajax->autoComplete list of results, and giving a result list back as the rendered view, if you use the mouse (and even the mouse wheel) to scroll results, all is well. Using the arrow keys, on the other hand, has the nasty effect of awkwardly scrolling the view: if I press down, the select box and the whole page move to the bottom of the browser's view pane; pressing up has the opposite effect of moving it to the top.

Has anyone else noticed this behaviour, and thought of something? the resulting list is provided by, e.g., this code (this gets $people from the autoComplete() function in the controller):

    <?php foreach($people as $person): ?>
  • <?php echo $person['Person']['id']; ?>
  • <?php endforeach; ?>

(Just an example, I actually show the id and name / surname / commercial name).

The CSS for the list is as follows:

div.auto_complete {
    position: absolute;
    width: 250px;
    background-color: white;
    border: 1px solid #888;
    margin: 0px; padding: 0px;
div.auto_complete ul{
    list-style: none;
    margin: 0px;