Non sono sicuro che così funzioni ma prova:

<asp;DataGrid id="DataGrid1" runat="server" Height="85px" Width="622px" AutoGenerateColumns="False" AllowPaging="True" PageSize="5" OnPageIndexChanged="DataGrid1_PageIndexChanged">
<AlternatingItemStyle Font-Size="9pt" Font-Names="verdana" HorizontalAlign="Center" ForeColor="#FEFEFC" BackColor="#A8A38A"></AlternatingItemStyle>
<ItemStyle Font-Size="9pt" Font-Names="verdana" HorizontalAlign="Center" ForeColor="#1B5C4B" BackColor="#DCDACE"></ItemStyle>
<HeaderStyle Font-Size="9pt" Font-Names="verdana" Font-Bold="True" ForeColor="#F2F0E7" BackColor="#1B5C4B"></HeaderStyle>
<Columns>
<asp:TemplateColumn HeaderText="Articolo">
<HeaderStyle HorizontalAlign="Center"></HeaderStyle>
<ItemTemplate>
<asp:Label id="Id_Art" runat="server" Text='<%# DataBinder.Eval(Container.DataItem, "IDARTICOLO") %>' />
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ForeColor="#000000" BackColor="#ffff00" BorderColor="#000000" Runat="server" ID="txt1"></asp:TextBox>
</EditItemTemplate>
</asp:TemplateColumn>
<asp:BoundColumn DataField="IDVERSIONE" ReadOnly="True" HeaderText="Descrizione">
<HeaderStyle HorizontalAlign="Center"></HeaderStyle>
</asp:BoundColumn>
<asp:TemplateColumn HeaderText="Prezzo">
<HeaderStyle HorizontalAlign="Center"></HeaderStyle>
<ItemTemplate>
<asp:Label id="Prezzo" runat="server" Text='<%# DataBinder.Eval(Container.DataItem, "PREZZOVENDITA") %>' />
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ForeColor="#000000" BackColor="#ffff00" BorderColor="#000000" Runat="server" ID="Textbox1"></asp:TextBox>
</EditItemTemplate>
</asp:TemplateColumn>
<asp:TemplateColumn HeaderText="Scheda Tecnica">
<HeaderStyle HorizontalAlign="Center"></HeaderStyle>
<ItemStyle HorizontalAlign="Center"></ItemStyle>
<ItemTemplate>
<asp:HyperLink id="Scheda" runat="server" Imageurl='<%# "images/divani_piccole/" &DataBinder.Eval(Container.DataItem,"FOTO1") %>' NavigateUrl='<%# "details.aspx?productID=" &DataBinder.Eval(Container.DataItem,"IDPRODOTTO ")& "&IMG_URL=" &DataBinder.Eval(Container.DataItem,"FOTO2") %>' Target=_blank runat="server" />
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ForeColor="#000000" BackColor="#ffff00" BorderColor="#000000" Runat="server" ID="Textbox2"></asp:TextBox>
</EditItemTemplate>
</asp:TemplateColumn>
<asp:TemplateColumn HeaderText="Carrello">
<HeaderStyle HorizontalAlign="Center"></HeaderStyle>
<ItemStyle HorizontalAlign="Center"></ItemStyle> </asp:TemplateColumn>
<asp:EditCommandColumn ButtonType="LinkButton" UpdateText="Update" CancelText="Cancel" EditText="Edit"></asp:EditCommandColumn>
</Columns>
</asp;DataGrid>

Cambia i due ; che ti ho messo nei tag <asp;DataGrid... e dimmi che succede