Since adding an OnSelect to my Datepicker, the TextChanged event no longer fires for this control. My code is as follows:
$(function() {
    $("#<%=txtStartDate.ClientID %>").datepicker({
        minDate: 0,
        dateFormat: 'dd-M-yy',
        onSelect: function(dateText, inst) {
            var theDate = new Date(Date.parse($(this).datepicker('getDate')));
            $("#<%=txtEndDate.ClientID %>").datepicker('option', 'minDate', theDate);
        }
    });
    $("#<%=txtEndDate.ClientID %>").datepicker({
        dateFormat: 'dd-M-yy'
    });
});
<%-- etc ---- %>
<asp:TextBox ID="txtStartDate" runat="server" AutoPostBack="true" OnTextChanged="txtStartDate_TextChanged"></asp:TextBox>
My other datepicker (txtEndDate) TextChanged event does fire so can only put it down to the OnSelect being defined for the txtStartDate control.
Greatly appreciate any help on this one. Cheers!