I've just migrated my project using jsonp longpolling on external domain to 0.5.2 version and I've got an HTTP 500 error on reconnect.
Connect & first message works fine but on reconnect I've got "object not set to an instance of an object" on my SignalR server.
My code was working on 0.5.1 version.
send a repro application
You could find a repro application on https://github.com/jlefebvre/BugSignalR
It's likely this issue #496
Fixed in the next version