The newest protocol conflicts with the old one, that's why I changed the server to the new version, and changed back again.
We must use a new port and a new protocol prefix. I have update the source on github a moment ago. Please download the newest one.
https://github.com/cctvsmg/yacoin-p2pool the newest version use a port 8338 like:
http://pool.bitcn.org:8338Please use some sane update mode when sending update to git...