I see this error in the console on safari. Doesn't happen in chrome, not sure what it is.
NodeBB v0.7.0-dev
[Error] Failed to load resource: the server responded with a status of 400 (Bad Request) (socket.io, line 0)
http://localhost:4567/socket.io/?EIO=3&transport=polling&t=1423763783601-136&sid=tCgKoHg8puuAEBodAAAY
I confirm the upgrade of the nginx increase the performance of nodebb. (index page was often realy slow / and some times crashes) The latest stable version of nxing has resolved this problems.