I use this every single day and it works perfectly. Are you using the default OSX terminal? If so you should try iTerm2 instead.
Ubuntu 14.04 server is running tmux.
I ssh into that server from an osx laptop and attach to the tmux session. After a ton of configuration mouse actions mostly work (copy/paste is always wonky).
I also ssh into that server from an Ubuntu laptop. The same configuration I needed to get mouse working for osx is no longer applicable.
I've never even thought of writing a screenrc and it's always worked great.