losing button.click events after initial biased postback updatepanel

i have page unparalleled instance usercontrol itself unparalleled updatepanel. inside updatepanel several symbol controls. click eventuality controls connected adult code-behind, init eventuality usercontrol.

i click eventuality initial symbol i push, each time, problem. after that, i wholly click events symbol (searchbutton) - rest ignored. i have enclosed formula control next - effect brevity, i have expelled click eventuality handler methods, nonetheless customary "void button_click(object sender, eventargs e)" variety. any ideas?

<asp:updatepanel id="pickerupdatepanel" runat="server" updatemode="conditional">
    <contenttemplate>
        <asp:panel id="container" runat="server">
            <div>
                <asp:textbox id="pickerresults" runat="server" style="margin-right: 3px;" skinid="plain" />
                <asp:image
                    id="launchpopup" runat="server" imageurl="~/images/icons/user_manage.png" 
                    imagealign="top" bordercolor="#294254" borderstyle="dotted" borderwidth="1px" 
                    height="20px" width="20px" style="cursor: pointer;" />
            </div>
            <asp:panel id="pickerpanel" runat="server" defaultbutton="okbutton" cssclass="popupdialog" style="height: 227px; width: 400px; padding: 5px; display: none;">
                <asp:panel runat="server" id="contactpickersearchparams" style="margin-bottom: 3px;" defaultbutton="searchbutton">
                    search: <asp:textbox id="searchterms" runat="server" style="margin-right: 3px;" width="266px" skinid="plain" />
                    <asp:button id="searchbutton" runat="server" text="go" width="60px" skinid="plain" />
                </asp:panel>
                <asp:listbox id="searchresults" runat="server" height="150px" width="100%" selectionmode="multiple" style="margin-bottom: 3px;" />
                <asp:button id="addbutton" runat="server" text="add >>" style="margin-right: 3px;" width="60px" skinid="plain" />
                <asp:textbox id="chosenpeople" runat="server" width="325px" skinid="plain" />
                <div style="float: left;">
                    <asp:button id="addnewcontact" runat="server" skinid="plain" width="150px" text="new contact" />
                </div>
                <div style="text-align: right;">
                    <asp:button id="okbutton" runat="server" text="ok" skinid="plain" width="100px" />
                </div>
                <input id="selectedcontacts" runat="server" visible="false" />
            </asp:panel>
            <ajax:popupcontrolextender id="pickerpopex" runat="server" popupcontrolid="pickerpanel" targetcontrolid="launchpopup" position="bottom" />
        </asp:panel>
   </contenttemplate>
   <triggers>
        <asp:asyncpostbacktrigger controlid="addbutton" eventname="click" />
        <asp:asyncpostbacktrigger controlid="searchbutton" eventname="click" />
        <asp:asyncpostbacktrigger controlid="addnewcontact" eventname="click" />
    </triggers>
</asp:updatepanel>

public biased category contactpicker : system.web.ui.usercontrol
{
    stable vacant page_init(object sender, eventargs e)
    {
        searchbutton.click += new eventhandler(searchbutton_click);
        addbutton.click += new eventhandler(addbutton_click);
        okbutton.click += new eventhandler(okbutton_click);
    }

    // formula left out
}