if (DropDownListFeeds.SelectedItem.Value=="All")
{
SPWeb web = SPContext.Current.Web;
SPSiteDataQuery query = new SPSiteDataQuery();
query.Lists =
"<Lists ServerTemplate=\"10000\"/>";
query.Query ="<OrderBy><FieldRef Name='Modified' Ascending='FALSE'>" +
"</FieldRef>" +
"</OrderBy>";
query.ViewFields = "<FieldRef Name='Title' /><FieldRef Name='Date' />";
query.Webs = "<Webs Scope='SiteCollection'/>";
query.RowLimit = 10;
DataTable doQuery = web.GetSiteData(query);
Repeater2.DataSource = doQuery;
Repeater2.DataBind();
<asp:Repeater ID="Repeater2" runat="server" onitemdatabound="Repeater2_ItemDataBound">
<ItemTemplate>
<%# Eval("Title")%>
</ItemTemplate>
<ItemTemplate>
<%# Eval("Date")%>
</ItemTemplate>

doQueryDataTable doesn't have aDatecolumn... Can you open the table in designer view and see if the column exists ? – Arsalan Adam Khatri Jan 30 at 13:21