[2008] What is wrong with this code? (SQL Command)

[Icyculyr]

Dim sqlCon As New SqlConnection("Data Source=ICYCULYR\SQLEXPRESS;Initial Catalog=test_kcDB;Integrated Security=True;Pooling=False")
        sqlCon.Open()
        Dim sqlCommand As New SqlCommand()
        sqlCommand.Connection = sqlCon
        Dim returnValue As Object = "Nothing"
        Select Case whichPreference
            Case PreferencesEnum.dblClickMenu
                sqlCommand.CommandText = ("SELECT preferences_value FROM dataTable")
                Dim sqlReader As SqlDataReader = sqlCommand.ExecuteReader()
                Dim tmpInt As Integer = 0
                While sqlReader.Read()
                    If tmpInt = whichPreference Then
                        returnValue = sqlReader.GetValue(tmpInt)
                        Exit While
                    End If
                    tmpInt += 1
                End While
        End Select
        sqlCon.Close()

the problem line is 'returnValue = sqlReader.GetValue(tmpInt)',
my value is DBNULL, but should return the first value of my column, which would be 'true'.

I assume sqlReader is reading the rows from my column 'preferences_value', so I don't see why it isn't working?
sqlReader.GetValue(tmpInt) (tmpInt being 0, as whichPreference is 0)
it should return the first row.

If anyone could help me with this?

Thanks