SQL Variable Declaration error

Question

I have the following form:

 Imports System.Data.SqlClient
Public Class Main
    Protected WithEvents DataGridView1 As DataGridView
    Dim instForm2 As New Exceptions
    Private Sub Button1_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles startpayrollButton.Click
        Dim ssql As String = "select MAX(payrolldate) AS [payrolldate], " & _
                 "dateadd(dd, ((datediff(dd, '17530107', MAX(payrolldate))/7)*7)+7, '17530107') AS [Sunday]" & _
                  "from dbo.payroll" & _
                  " where payrollran = 'no'"
        Dim oCmd As System.Data.SqlClient.SqlCommand
        Dim oDr As System.Data.SqlClient.SqlDataReader
        oCmd = New System.Data.SqlClient.SqlCommand

        Try
            With oCmd
                .Connection = New System.Data.SqlClient.SqlConnection("Initial Catalog=mdr;Data Source=xxxxx;uid=xxxxx;password=xxxxx")
                .Connection.Open()
                .CommandType = CommandType.Text
                .CommandText = ssql
                oDr = .ExecuteReader()
            End With
            If oDr.Read Then
                payperiodstartdate = oDr.GetDateTime(1)
                payperiodenddate = payperiodstartdate.AddDays(7)
                Dim ButtonDialogResult As DialogResult
                ButtonDialogResult = MessageBox.Show("      The Next Payroll Start Date is: " & payperiodstartdate.ToString() & System.Environment.NewLine & "            Through End Date: " & payperiodenddate.ToString())
                If ButtonDialogResult = Windows.Forms.DialogResult.OK Then
                    exceptionsButton.Enabled = True
                    startpayrollButton.Enabled = False
                End If
            End If
            oDr.Close()
            oCmd.Connection.Close()
        Catch ex As Exception
            MessageBox.Show(ex.Message)
            oCmd.Connection.Close()
        End Try

    End Sub
    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles exceptionsButton.Click
        Dim adapter As System.Data.SqlClient.SqlDataAdapter
        Dim connection As System.Data.SqlClient.SqlConnection
        Dim connectionString As String = "Initial Catalog=mdr;Data Source=xxxxx;uid=xxxxx;password=xxxxx"
        Dim ds As New DataSet
        connection = New SqlConnection(connectionString)
        Try
            connection.Open()
            adapter = New SqlDataAdapter("SELECT [Exceptions].Employeenumber,[Exceptions].exceptiondate, [Exceptions].starttime, [exceptions].endtime, [Exceptions].code, datediff(minute, starttime, endtime)  as duration INTO scratchpad3" & _
      " FROM Employees INNER JOIN Exceptions ON [Exceptions].EmployeeNumber = [Exceptions].Employeenumber" & _
      " where [Exceptions].exceptiondate between @payperiodstartdate and @payperiodenddate" & _
      " GROUP BY [Exceptions].Employeenumber, [Exceptions].Exceptiondate, [Exceptions].starttime, [exceptions].endtime," & _
      " [Exceptions].code, [Exceptions].exceptiondate", connection)
            If (ds Is Nothing) Then
                'it's empty
                MsgBox("There was no data for this time period, press Ok to continue", "No Data")
                connection.Close()
                Exceptions.Hide()
            Else 
                adapter.Fill(ds)
                connection.Close()
            End If

        Catch ex As Exception
            MessageBox.Show(ex.ToString)
            connection.Close()
        End Try
        Exceptions.Show()
    End Sub
    Private Sub DataGridView1_CellContentClick(ByVal sender As System.Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles DataGridView1.CellContentClick

    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

    End Sub
End Class

and when I run my app, I get a SQL error that tells me that I need to declare a value for '@payperiodstartdate' but I know that that value is declared because the first query runs fine. I am told that the line where the error is is line 59, which is this line:

  adapter.Fill(ds)

Can someone please tell me what I may be missing?

Thank you

Doug