Michel,
That seems to be it.
On both Windows and Ubuntu, if I access the the ISY using http, I do not get Current State information or any Event Logs. If I access it using https, then I do get that information and the ISY Java Administrative Console seems to work just as it should.
I tested this 3 times in each scenario (Ubunutu Firefox/http, Ubuntu Firefox/https, Win7 Chrome/http, Win7 Chrome/https). In all cases, http failed, but https was successful. That may be coincedence but I think you are on to something here. I would have never thought that the jar app changed its communication protocol depending upon the way the browser called it.