SqlDataReader.HasRows returns false since SQL 2008 upgrade

Question

I've got an ASP.NET 2.0 website that connects to a SQL database. I've upgraded the SQL server from 2000 to 2008 and since then, one page refuses to work.

I've worked out the problem is that the call to SqlDataReader.HasRows is returning false even though the dataset is not empty and removing the check allows the loop through reader.Read() to access the expected data.

    _connectionString = WebConfigurationManager.ConnectionStrings["SQLServer"].ConnectionString;
    SqlConnection connection = new SqlConnection(_connectionString);
    SqlCommand command = new SqlCommand(searchtype, connection);
    SqlParameter _parSeachTerm = new SqlParameter("@searchterm", SqlDbType.VarChar, 255);
    _parSeachTerm.Value = searchterm;
    command.Parameters.Add(_parSeachTerm);
    command.CommandType = CommandType.StoredProcedure;
    try
    {
        connection.Open();
        SqlDataReader reader = command.ExecuteReader();
        if (reader.HasRows) //this always returns false!?
        {
            while (reader.Read())
            {...

Does anybody have any idea what's going on? There are similar code blocks on other pages where HasRows returns the correct value.

EDIT- Just to clarify, the stored procedure DOES return results which I have confirmed because the loop runs through fine if I remove the HasRows check. Changing just the name of the SQL server in the connection string to an identical database running on SQL 2000 makes the problem go away. I've checked that NOCOUNT is off, so what else could make HasRows return false when that's not the case??

EDIT2- Here's the SP

CREATE PROCEDURE StaffEnquirySurnameSearch

@searchterm varchar(255)

AS

SELECT  AD.Name, AD.Company, AD.telephoneNumber, AD.manager, CVS.Position, CVS.CompanyArea, CVS.Location, CVS.Title, AD.guid AS guid,
AD.firstname, AD.surname
FROM ADCVS AD
LEFT OUTER JOIN CVS ON
AD.Guid=CVS.Guid 
WHERE AD.SurName LIKE @searchterm
ORDER BY AD.Surname, AD.Firstname
GO

Many thanks in advance.

Answer 1

Does the stored procedure work if you invoke it in directly, say in SSMS? I'd start by making sure that it does.

Answer 2

HasRows requires a scrollable cursor.

Do the rows you are bringing back contain any large image/BLOB data?

As someone else suggested, I think posting the Stored Procedure might throw some light on the matter...