C# - DataTable From Session Memory Has No Columns

Im trying to retrieve a datatable that I put into a session variable, however when i do it apears that there are no columns... I have done this before in VB.NET, I'n now using C#, and it worked perfectly, and as far as i can see there is no change in the code other than the obvious syntax changes.

EDIT: The dt (in part 2) variable has the right data when i look in the data visulization window, but i have noticed that the other properties associated with a datatable are abscent. When i hover over a normal looking datatable with my mouse it looks like the following: " dt ----- {System.Data.DataTable}" but in the class im working on it just looks like "dt ----- {}". Also, after I return the session variable into the dt I clone it (dtclone = dt.clone(); ) and the clone is empty in the data visulizer.... what on earth!

EDIT 2: I have now also tried converting the first datatable to a dataset, putting this in the session variable, and recoverting it back to a datatable in the class. Am starting to wonder if it is a probelm with: dt.Load(sqlReader); The data does appear after this step though in the dataset visualiser, but not after being cloned. Code below.

1) SQL command in a webhandler, the results of which populate the datatable to be put into the session variable.

DataTable dt = new DataTable();
SqlDataReader sqlReader= default(SqlDataReader);
SqlDataAdapter sqlAdapter = new SqlDataAdapter();
sqlReader = storedProc.ExecuteReader(CommandBehavior.CloseConnection);
dt.Load(sqlReader);
System.Web.HttpContext.Current.Session["ResultsTable"] = dt;

2) Part of the code in a class which performs calculations on the table:

DataTable dt = (DataTable)HttpContext.Current.Session["ResultsTable"];