I have Windows 7 Enterprise. With version 35 Firefox lost connection, the only way to make it work is to close it and reopen. I look for some fix in the support pages but there is no answer. The only similar issue suggests it's a firewall issue, but even if disconnect my computer firewall this still happens. At home there is a Windows 8.1 professional computer with the same issue. I upgrade to version 36 expecting this issue is fixed but it doesn't. I installed different windows browsers (Chrome, Iron, Tor, Opera) the only one with this issue is Firefox. Behavior make really unlikely to be a firewall issue.