Column 'coloumname' Does Not Belong To Table Categories .

I have a simple Stored Procedure with multiple select statements..doing

select linkid,linkdesc from links;select cateid,cate from categories... for example.

I created a dataset and then fill the tables

 see the code below
,CS 
 DataSet ds = Obj.GetDataSet("query here);

            dlc.DataSource = ds.Tables[0];
            DataTable llist = ds.Tables[1];
            if (llist.Rows.Count > 7)
            {
                dr = ds.Tables[1].Rows[7];
                dr["cateid"] = 0;
                dr["cate "] = "more...";               
            }
            else
            {
                System.Data.DataRow newDataRow = llist.NewRow();               
                newDataRow["cateid"] =0;
                newDataRow["cate "] = "more...";
                llist.Rows.Add(newDataRow);
               
            }
  lls.DataSource = ds.Tables[1];DataBind();
 .ASPX
<asp:DataList ID="lls" RepeatColumns="4" runat="server" RepeatDirection="Horizontal"
                                CellPadding="4" CellSpacing="4" BorderWidth="0" Width="100%">
                                <ItemTemplate>
                                    <asp:HyperLink  Text='<%# Eval("cate") %>' CssClass='<%# "mcs" + Eval("cate").ToString()%>' NavigateUrl='<%# PickURL(Eval("cateid").ToString(),Eval("cate").ToString()) %>'
                                        runat="server" />
                                </ItemTemplate>
                                <FooterStyle HorizontalAlign="right" />
                            </asp:DataList>
 
but  ITS WORKING FINE SOME TIMES ONLY , FEW TIMES ERROR OCCURRED  THE ERROR IS

 Column 'cate' does not belong to table
Table1.
 I DON'T KNOW WHY THIS ERROR IS  COME ANY BODY HAVING SOLUTION TO RESOLVE THIS PROBLEM 
 DETAILED ERROR MESSAGE: 
Server Error in '/' Application.
Column 'lname' does not belong to table
Table1.
Description: An unhandled exception occurred during the execution of
the current web request. Please review the stack trace for more information
about the error and where it originated in the code.

Exception Details:
System.ArgumentException: Column 'lname' does not belong to table
Table1.

Source Error:

An unhandled exception was generated during
the execution of the current web request. Information regarding the origin and
location of the exception can be identified using the exception stack trace
below.

Stack Trace:

[ArgumentException: Column 'lname' does not
belong to table Table1.]
System.Data.DataRow.GetDataColumn(String columnName)
+1887619
System.Data.DataRow.set_Item(String columnName, Object value)
+14
state_common_index.FillIndexPage()
+590
state_common_index.Page_Load(Object sender, EventArgs e)
+1203
System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o,
Object t, EventArgs e)
+15
System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender,
EventArgs e) +34
System.Web.UI.Control.OnLoad(EventArgs e)
+99
System.Web.UI.Control.LoadRecursive()
+47
System.Web.UI.Control.LoadRecursive()
+131
System.Web.UI.Control.LoadRecursive()
+131
System.Web.UI.Control.LoadRecursive()
+131
System.Web.UI.Control.LoadRecursive()
+131
System.Web.UI.Page.ProcessRequestMain(Boolean
includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1061