Error when sending by HTTP (error code 200, error text OK)

We receive a quantity of messages everyday that "sometimes", for some

strange reason, seem to fail in XI, with the message:

<SAP:Code area="INTERNAL">HTTP_RESP_STATUS_CODE_NOT_OK</SAP:Code>

<SAP:P1>200</SAP:P1>

<SAP:P2>OK</SAP:P2>

<SAP:Stack>HTTP response contains status code 200 with the description

OK System error in parser</SAP:Stack>

We checked out note 871959 but we are in a higher SP release XI 3.0

(14), and the corrections are implemented.

Any other reccomendations?