Outbound Message Error - java.io.IOException: Stream closed

Hi all - I am trying to find clarification and resolutio on the java error experienced from an Outbound Message to a Jitterbit Server. It appears as though the connection is getting closed before the response is sent to Salesforce OR that Jitterbit cannot communicate back to Salesforce.

First let me mention - Jitterbit themselves has confirmed my configuration is correct and troubleshooted through the entire server setup with no result. They think Salesforce may be blocking. Interestingly enough, this is a Jitterbit migration...we currently have an older server set up running the exact same operations with no problems.

1. Outbound message triggered when update to Account Object.
2. SOAP request sent to Jitterbit HTTP endpoint & consumes the WSDL and successfully maps the data to a local Oracle DB
3. But the Operation has no evidence in the log that it runs
4. SFDC displays the error: java.io.IOException: Stream closed

I've tested this with SoapUI using the HTTP Endpoint on the server, and i successfully get an ACK. The only thing that stands out is that the Connection says "Keep-alive" when I kind of expect it to say "Closed"

The request also correct references the right SSL Cert on the server, we're using HTTPS and this fails even when all ports/network firewalls/IP ranges are open.