Updating SQL from Gridview Checkbox Object reference not set to an instance of an object

Hello,
I know this is a common question.  I have a gridview and 2 cells have a checkbox.  I'm updating the data to a SQL table.  It comes up with error:
Object reference not set to an instance of an object.

I was updating this to Access and now the table is being moved to SQL and it's erroring out.

Using asp.net vb
aspx page:
<asp:GridView ID="gvEmployees" runat="server" AllowSorting="True" AutoGenerateColumns="False" DataKeyNames="EmpID" DataSourceID=""  AllowPaging="False">
<Columns>

<asp:TemplateField HeaderText="Transfer" SortExpression="Transfers">
<EditItemTemplate><div align="center">
<asp:CheckBox ID="CheckBox1" runat="server" Checked='<%# IIf(Eval("Transfers") Is DBNull.Value, "False", Eval("Transfers")) %>' /></div>
</EditItemTemplate>
<ItemTemplate>
<div align="center">
<asp:CheckBox ID="Transfers" runat="server" Checked='<%# IIf(Eval("Transfers") Is DBNull.Value, "False", Eval("Transfers")) %>'
      Enabled="false" /></div>
</ItemTemplate>
</asp:TemplateField>

<asp:TemplateField HeaderText="Promo" SortExpression="Promotions">
<EditItemTemplate><div align="center">
<asp:CheckBox ID="chkPromotions" runat="server" Checked='<%# IIf(Eval("Promotions") Is DBNull.Value, "False", Eval("Promotions")) %>' /></div>
</EditItemTemplate>
<ItemTemplate><div align="center">
<asp:CheckBox ID="chkPromotions" runat="server" Checked='<%# IIf(Eval("Promotions") Is DBNull.Value, "False", Eval("Promotions")) %>'
      Enabled="false" /></div>
</ItemTemplate>
</asp:TemplateField>            

<asp:CommandField ShowEditButton="True" ButtonType="Button" />
 </Columns>
</asp:GridView>

aspx.vb page
Imports System.Data
Imports System.Data.SqlClient

Imports DataSetClassIntranetSQL  (This gets the connection string)


Protected Sub gvEmployees_RowUpdating(sender As Object, e As GridViewUpdateEventArgs) Handles gvEmployees.RowUpdating
gvEmployees.EditIndex = -1

Dim strChange, strFrom, strTo As String
Dim strEmpID, strSQL As String
Dim intEmpID, recordUpdated As Integer

strEmpID = (DirectCast(gvEmployees.Rows(e.RowIndex).FindControl("lblEmpID"), Label).Text)
intEmpID = CInt(strEmpID)

Dim ckTfr As Boolean
ckTfr = DirectCast(gvEmployees.Rows(e.RowIndex).FindControl("Transfers"), CheckBox).Checked

Dim ckPromo As Boolean
ckPromo = DirectCast(gvEmployees.Rows(e.RowIndex).FindControl("chkPromotions"), CheckBox).Checked

strSQL = "SELECT empID, Promotions, Transfers FROM Employees WHERE empID = " & intEmpID & " "

Try
ds = GetDataSet(strSQL)

Catch ex As Exception
lbl1.Text = "Unable to retrieve ds: " & ex.ToString

End Try

With ds.Tables(0).Rows(0)
.Item("Promotions") = ckPromo
.Item("Transfers") = ckTfr

End With

recordUpdated = EmployeePhone.UpdateData(ds, strSQL)
ds.Dispose()
gvEmployees.EditIndex = -1

BindData()
End Sub

Any ideas?