I was having problem with Esignal 10 as well. After many hours of converstation with Esignal I realized that my page had somehow been corrupted. I recreated my main page and the system has been stable for the last 10 days.

The earlier post also referred to TOS. In my humble opinion, thinkorswim is a must have for serious option traders. It would be hard for me to imagine trading complex option strategies without their analytic tools.