Session gone after opening a new tab within Internet explorer / Google Chrome

So let's eliminate a few factors. In the Fiddler traces you say the jsessionid stays the same. I'm assuming you mean in both tabs? If you enable cookie persistence, does that cookie change, or do you notice the client getting load balanced to a different server? What is different about the client's first request to the second tab and it's last request to the first tab? I'm talking about headers, cookies and anything else in the request payload. Last, what happens when the app fails? What does the server send to the client, and what is the last thing the client sends before the failure?