HI all,

This is a strange one. I have 2 image buttons. One is for sorting, the other opens a panel with a button in it to do filtering.

If I click the image button to filter, choose my filter criteria, then click the button to do the actual filtering everything works great.

Likewise, if I click the image button to sort everything works great.

HOWEVER, After filtering 5 times in a row successfully (or however many times, the count is irrelevant), then I sort, all of a sudden the image button to filter won't fire.

Both buttons that trigger an action are in an asp:updatepanel.

Code:
            <asp:AsyncPostBackTrigger
                ControlID="ibtnSortName" />
            <asp:AsyncPostBackTrigger
                ControlID="btnFilterName" />
ibtnSortName fires the sort routine and btnFilterName firest the filter routine.

Here's the code that contains those buttons:

Code:
                                        <td class="50PctNoBorderRight">
                                            <asp:ImageButton
                                                ID="ibtnFilterName"
                                                runat="server" 
                                                ImageUrl="~/images/filter.png"
                                                AlternateText="Filter Name" 
                                                OnClientClick="return false;" />
                                            <asp:Panel ID="pnlFilterName" 
                                                runat="server" 
                                                CssClass="FilterPopupControl" >
                                                Select the Specific Name You Wish To View
                                                <br />
                                                <asp:ListBox 
                                                    ID="lstName" 
                                                    runat="server" 
                                                    SelectionMode="Multiple" 
                                                    CssClass="HomeFilter">
                                                </asp:ListBox>
                                                <br />
                                                <asp:ImageButton 
                                                    ID="btnFilterName" 
                                                    runat="server" 
                                                    OnClick="btnFilterName_Click" 
                                                    ImageUrl="~/images/buttons/btn_submit.png" />
                                            </asp:Panel>
                                            <asp:ImageButton 
                                                ID="ibtnSortName" 
                                                runat="server" 
                                                ImageUrl="~/images/sort_asc2.png" 
                                                onclick="ibtnSortName_Click"
                                                AlternateText="Sort Name" />                            
                                        </td>
And here's the popup control extender i use to display the filter area:
Code:
            <asp:PopupControlExtender 
                ID="pceFilterName" 
                runat="server" 
                TargetControlID="ibtnFilterName" 
                PopupControlID="pnlFilterName" 
                Position="Bottom" 
                CommitProperty="value">
            </asp:PopupControlExtender>
The bizarre behavior I can't figure out is that the ibtnSortName ALWAYS works and fires the code behind. The btnFilterName stops firing the code behind only after I click the ibtnSortName. If I never sort, the btnFilterName always works.

I've looked at the html source to see if anything is different ( I sorted then resorted so the order would be exactly the same) and the HTML is exactly the same in both the pre-sorted and post-sorted iterations.

Anyone have any ideas? If it were just that the code behind were not acting properly, I could easily fix this. But the code behind just stops getting triggered?

Thanks,
Jon