paypal ipn works in sandbox but not live?

Hi
The following code works in sandbox but not live the ipn message reads as sent and returns a 200 message so I presume this works ok.
the database is not updated though but is when in sandbox. I havent installed msxml would this make a differenc as the ipn message completes with a 200 message




<%@LANGUAGE="VBScript"%><%dim ipnok
ipnok="no"

%><%
Dim Item_name, Item_number, Payment_status, Payment_amount
Dim Txn_id, Receiver_email, Payer_email
Dim objHttp, str
' read post from PayPal system and add 'cmd'
str = Request.Form & "&cmd=_notify-validate"
' post back to PayPal system to validate
set objHttp = Server.CreateObject("Msxml2.ServerXMLHTTP")
' set objHttp = Server.CreateObject("Msxml2.ServerXMLHTTP.4.0")
' set objHttp = Server.CreateObject("Microsoft.XMLHTTP")
objHttp.open "POST", "https://www.sandbox.paypal.com/cgi-bin/webscr", false
objHttp.setRequestHeader "Content-type", "application/x-www-form-urlencoded"
objHttp.Send str
' assign posted variables to local variables
Item_name = Request.Form("item_name")
Item_number = Request.Form("item_number")
Payment_status = Request.Form("payment_status")
Payment_amount = Request.Form("mc_gross")
Payment_currency = Request.Form("mc_currency")
Txn_id = Request.Form("txn_id")
Receiver_email = Request.Form("receiver_email")
Payer_email = Request.Form("payer_email")
' Check notification validation
if (objHttp.status <> 200 ) then
' HTTP error handling
elseif (objHttp.responseText = "VERIFIED") then
ipnok="yes"
' check that Payment_status=Completed
' check that Txn_id has not been previously processed
' check that Receiver_email is your Primary PayPal email
' check that Payment_amount/Payment_currency are correct
' process payment
elseif (objHttp.responseText = "INVALID") then
' log for manual investigation
else
' error
end if
set objHttp = nothing
%><% if ipnok="yes" then%><% 'Dimension variables
Dim adoCon           'Holds the Database Connection Object
Dim rsUpdateEntry    'Holds the recordset for the record to be updated
Dim strSQL           'Holds the SQL query to query the database
Dim lngRecordNo      'Holds the record number to be updated

'Read in the record number to be updated
if Request.Form("item_number")=("") then 
Response.End

end if

lngRecordNo = CLng(Request.Form("item_number")) 


	'Create an ADO connection object
Set adoCon = Server.CreateObject("ADODB.Connection")

'Set an active connection to the Connection object using a DSN-less connection
adoCon.Open "Provider=Microsoft.Jet.OLEDB.4.0; Data Source=" & Server.MapPath("/database.mdb")


'Set an active connection to the Connection object using DSN connection
'adoCon.Open "DSN=guestbook"


'Create an ADO recordset object
Set rsUpdateEntry = Server.CreateObject("ADODB.Recordset")

'Initialise the strSQL variable with an SQL statement to query the database
strSQL = "SELECT * FROM tbl WHERE N_ID=" & lngRecordNo 	
'Set the cursor type we are using so we can navigate through the recordset
rsUpdateEntry.CursorType = 2 	
 	'Set the lock type so that the record is locked by ADO when it is updated
rsUpdateEntry.LockType = 3 	


'Open the recordset with the SQL query
rsUpdateEntry.Open strSQL, adoCon


'Update the record in the recordset
rsUpdateEntry.Fields("N_av") = "(Sold)"


'Write the updated recordset to the database
rsUpdateEntry.Update


'Reset server objects
rsUpdateEntry.Close
Set rsUpdateEntry = Nothing
Set adoCon = Nothing


'Return to the update select page in case another record needs deleting
Response.End

%> <% elseif  ipnok="no" then
Response.End
%><%else%><%end if%>