python - qbxml event subscription behaving erratically -

i tried receive notifications when sales receipts created in quickbooks. qbxml:

<?xml version="1.0" encoding="utf-8"?> <?qbxml version="13.0"?> <qbxml>   <qbxmlsubscriptionmsgsrq>     <dataeventsubscriptionaddrq>       <dataeventsubscriptionadd> <!-- required -->         <subscriberid >{d8a63411-5965-4701-b2d6-eda9b2f938da}</subscriberid> <!-- required -->         <comcallbackinfo> <!-- required -->           <appname >testapp</appname> <!-- required -->           <progid>callback.server</progid> <!-- optional -->         </comcallbackinfo>         <!-- deliverypolicy may have 1 of following values: deliveralways, deliveronlyifrunning -->         <deliverypolicy >deliveralways</deliverypolicy> <!-- required -->         <txneventsubscription> <!-- optional, may repeat -->           <!-- txneventtype may have 1 of following values: arrefundcreditcard, bill, billpaymentcheck, billpaymentcreditcard, charge, check, creditcardcharge, creditcardcredit, creditmemo, deposit, estimate, inventoryadjustment, invoice, itemreceipt, journalentry, purchaseorder, receivepayment, salesorder, salesreceipt, salestaxpaymentcheck, timetracking, vendorcredit -->           <txneventtype >salesreceipt</txneventtype> <!-- required, may repeat -->           <!-- txneventoperation may have 1 of following values: add, modify, delete -->           <txneventoperation >add</txneventoperation> <!-- required, may repeat -->         </txneventsubscription>       </dataeventsubscriptionadd>     </dataeventsubscriptionaddrq>   </qbxmlsubscriptionmsgsrq> </qbxml> 

in comcallbackinfo tag have specified callback progid callback.server. callback server python script:

import win32com.server.register import ctypes  class srv:     _reg_clsid_ = "{7cc9f362-486d-11d1-bb48-0000e838a65f}"      _reg_desc_ = "python test com server"      _reg_progid_ = "callback.server"   if __name__ == "__main__":     win32com.server.register.usecommandline(srv)  ctypes.windll.user32.messageboxw(0, "you created sales receipt", "congrats", 1) 

i sent qbxml using sdktestplus3 bundled sdk. first time sent qbxml, worked fine, , received "status ok" response quickbooks. if tried sending qbxml again, got following response:

<?xml version="1.0" ?> <qbxml>    <qbxmlsubscriptionmsgsrs>       <dataeventsubscriptionaddrs statuscode="3180" statusseverity="error" statusmessage="there error when saving subscription. " />    </qbxmlsubscriptionmsgsrs> </qbxml> 

i figured because subscription saved, when used "subscription viewer" bundled sdk, says no subscriptions exist.

to add confusion, when start quickbooks , save first sales receipt, callback application works (i see little popup)... once. sales receipts save after not anything, have restart quickbooks work again.

any appreciated!!!