Second ModalPopUpExtender on a Form Not Displaying

I have an update panel with two ModalPopUpExtenders, when I display the first all is good, but when I try to display the second it will not display. I'm a little at a loss. I've seen lots of examples of having multiple ModalPoopUpExtenders on the same page so I'm pretty sure this is possible.
Here is my code:
<asp:ModalPopupExtender ID="mpeLogEntry" runat="server" PopupControlID="pnlLogEntry" RepositionMode="RepositionOnWindowResizeAndScroll" TargetControlID="ibAddLogEntry" BackgroundCssClass="modalBackground"> </asp:ModalPopupExtender> <asp:ModalPopupExtender ID="mpeErrorMessage" runat="server" PopupControlID="pnlError" RepositionMode="RepositionOnWindowResizeAndScroll" TargetControlID="ibError" BackgroundCssClass="modalBackground"> </asp:ModalPopupExtender> <asp:Panel ID= ...