I haven't had much time to investigate but just quickly using the packet debugger, I'm discovered that room joins to names that contain a single quote character(') are not possible. It doesn't even get to the captcha. However, other rooms that are just alphanumeric names do work.
Like I said, I haven't investigated much but my first guess would be that there's a problem in parsing the room name.
gyach-i ver 1.1.0