Dear experts,

I have an UpdatePanel and some controls within it, as you can see below. If I change a number in txtGoToPage textbox and press Enter, GoToPage_TextChanged() event handler is called. But if I enter first any page number other than 1, press Enter, and then enter number 1 again, after pressing Enter GoToPage_TextChanged() is not called. The same problem exists with ddlPageSize dropdown list. As you can see, by default the third item is selected. If I select another item, ddlPageSize_SelectedIndexChanged() is called, but if after that I select the third (initially selected) item, ddlPageSize_SelectedIndexChanged() is not called.

Could you please help me fix that?

Thanks.

Code:
    <asp:UpdatePanel ID="upnlLicensing" runat="server" UpdateMode="Conditional" >
        <ContentTemplate>
...
            <asp:Label ID="Label1" runat="server" Text="Show rows:" />
            <asp:DropDownList ID="ddlPageSize" runat="server" AutoPostBack="true"
                OnSelectedIndexChanged="ddlPageSize_SelectedIndexChanged">
                <asp:ListItem Value="20" />
                <asp:ListItem Value="50" />
                <asp:ListItem Value="100" Selected="True" />
            </asp:DropDownList>
            &nbsp;
            Page 
            <asp:TextBox ID="txtGoToPage" runat="server" AutoPostBack="true" 
                OnTextChanged="GoToPage_TextChanged" CssClass="gotopage" onchange="JSSetSessionValue('ReloadLicensing', true);JSSetSessionValue('NewPageNumber', this.value)" />
            of
            <asp:Label ID="lblTotalNumberOfPages" runat="server" />
                
        </ContentTemplate>
    </asp:UpdatePanel>