Autopostback Problems with IE 10

Hello Everyone and thanks for your help in advance.  Several years ago, I built a webform application that utilizes a autopostback:
<asp:DropDownList ID="ddlCategory" runat="server" AutoPostBack="True"> <asp:ListItem Value="correspondence">Correspondence</asp:ListItem> <asp:ListItem Value="labs">Labs</asp:ListItem> <asp:ListItem Value="radiology">Radiology</asp:ListItem> </asp:DropDownList> This has worked fine up until our introduction of Surface tablets using IE 10, in which this fails to work.  When changed to compatability mode, it does work fine, however, I need to make provisions for users who don'tthink of that.  Obviously, I can create a submit button to accomplish the behavior, but wondered if anyone else has run into this and how they handled it.  Any feedback would be greatly apprecia ...