Asp.net asp:ListBox在chrome内部单击时结巴

我在ModalPopupXtender中的表中并排有2个asp:ListBox控件，每次在Chrome浏览器中单击这些列表框时，都会发出一种口吃，就像在屏幕上重新绘制一样。这种行为只发生在Chrome上，IE9、Safari和Firefox也进行了测试

代码：

使用：最新的AjaxControlToolkit和.NET 4

口吃的原因是什么？如何消除它？

设置AutoPostBack=True解决了它

<tr id="Tr1">
    <td>
        <asp:ListBox ID="ListBoxAvailableChannels" runat="server" Width="300px" Height="500px"
            DataSourceID="ObjectDataSourceAvailableChannels" DataTextField="Name" DataValueField="Id"
            AutoPostBack="True"></asp:ListBox>
        <asp:ObjectDataSource ID="ObjectDataSourceAvailableChannels" runat="server" SelectMethod="GetAvailableChannelList"
            TypeName="PlayerDataProvider"></asp:ObjectDataSource>
    </td>
    <td>
        <table>
            <tr>
                <td>
                    <asp:ImageButton ID="ImageButtonAddChannel" runat="server" ImageUrl="~/Icons/Arrows/right.png" />
                </td>
            </tr>
            <tr>
                <td>
                    <asp:ImageButton ID="ImageButtonRemoveChannel" runat="server" ImageUrl="~/Icons/Arrows/left.png" />
                </td>
            </tr>
        </table>
    </td>
    <td>
        <asp:ListBox ID="ListBoxPlayerChannels" runat="server" Width="300px" Height="500px"
            DataSourceID="ObjectDataSourcePlayerChannels" DataTextField="Name" DataValueField="Id"
            AutoPostBack="True"></asp:ListBox>
        <asp:ObjectDataSource ID="ObjectDataSourcePlayerChannels" runat="server" SelectMethod="GetPlayerChannelList"
            TypeName="PlayerDataProvider">
            <SelectParameters>
                <asp:SessionParameter DefaultValue="" Name="p_playerId" SessionField="SelectedPlayerId"
                    Type="String" />
            </SelectParameters>
        </asp:ObjectDataSource>
    </td>
</tr>