SignalR/SignalR — pull request #104 by AkosLukacs (2011-12-21 17:20:09+00:00)
Title: Found an issue: some ancient browsers (for example Mozilla 5.0, running ...

...in Cisco Digital Media Player 4400G) do not set content-length header at all when issuing a POST without actual data. And that makes IIS to return a HTTP 411 Length Required error, breaking SignalR communication.

The first negotiate request did exactly that, spent roughly half a day when finally could catch this with WireShark.

Simply changing
data: {}
to
data: {'x':'x'}
solves this issue.

Great work anyway :)