Query for table column names returns no results to the calling code

Question

I have a stored procedure query that I want to return the details of columns within a specific table. When I run the sp in Sql server managements studio I get results returned. The problem is when I try to execute the query from C# code. There are no exceptions thrown and the relevant persmissions are granted to execute the procedure in the database but no results are returned to the code. I'm using the enterprise application block version 3.1.

This is my query

    SELECT   SysObjects.[Name] as TableName,
             SysColumns.[Name] as ColumnName,
             SysTypes.[Name] As DataType,
             SysColumns.[Length] As Length
    FROM    SysObjects INNER JOIN SysColumns   ON SysObjects.[Id] = SysColumns.[Id]
    INNER JOIN SysTypes  ON SysTypes.[xtype] = SysColumns.[xtype]
    WHERE  SysObjects.[type] = 'U'
        AND SysObjects.[Name] = 'MyTableName'
    ORDER BY  SysObjects.[Name]

C# Calling code

using (DbCommand dbCommand = db.GetStoredProcCommand("StoredProcedureName"))
{
    DataSet data = new DataSet();

    db.LoadDataSet(dbCommand, data, "MyTableName");
    if (data.Tables.Count > 0 && data.Tables[0].Rows.Count > 0)
    {
        // Do stuff with the returned data
    }
}