Auto_complete_field works for all BUT Opera

The following code works fine for all browser except Opera..
Opera does not update the textfield selection when I select one of the
item from the pop-up list and press "Enter"...

Is there any way I could force the broswer to update the selected item
into params
before calls into action so this way it will work under Opera also?

any help is appreciated...

<td>
                                <%= text_field "portal", "searchtext" -
%>

                                <div class="auto_complete"
id="portal_searchtext_auto_complete">

                                </div>

                                <%=
auto_complete_field :portal_searchtext,
                                :url =>{:controller=> 'portal',
                                :action => 'venue_site_live_search' },
                                :frequency => 0.2,
                                :update
=>"portal_searchtext_auto_complete",
                                :indicator =>"ajax-loader",
                                :token =>","
                                -%>
</td>