Not In List

[DD]

I use Not In List on my frmOrder customerIDwhich in turn opens
frmCustomer (openArgs) after entering in a new customer and closing
the form the customer appears in frmOrder, however this is also where
it fails as i recieve #error in some fields on the form and not
others.
And i have to close the form and reopen for it to accept the new
customer

This problem does not happen in XP PRO

any ideas would be appreciated

My not in list code:
Private Sub CustomerID_NotInList(NewData As String, Response As
Integer)
Dim db As DAO.Database
Dim rs As DAO.Recordset

Dim strMsg As String
strMsg = "Do you want to add " + NewData + " to the list?"
strMsg = strMsg & vbCrLf & "Click Yes to add the new Customer"
strMsg = strMsg & vbCrLf & "Click No to select a Customer from the
list."
If MsgBox(strMsg, vbQuestion + vbYesNo, "Customer Not Found!") =
vbNo Then

Response = acDataErrContinue
Else

DoCmd.OpenForm "frmCustomer", , , , , acDialog, "GotoNew"
Response = acDataErrAdded

If CustomerID <> 0 Then Me![CustomerID] = CustomerID

Exit_CustomerID_NotInList:
Exit Sub

Err_CustomerID_NotInList:
MsgBox Err.Description
Resume Exit_CustomerID_NotInList
End If
End Sub