Works perfectly fine for me with Firefox 13 on win32. That part of the debug log states the same. What does not work after you connected? Is this with your own implementation or with the echo test from websocket.org?
Always read the online manual(wiki), FAQ(wiki) and search the forum before posting.
Do not e-mail Team Kodi members directly asking for support. Read/follow the forum rules(wiki).
Please read the pages on troubleshooting(wiki) and bug reporting(wiki) before reporting issues.