Whenever I reattach to my detached screen (containing Irssi), my Putty screen is resized to something it has been at startup. If I change the window size after this, detach the screen and resize it ...
So. I am using PuTTY to connect to a remote server that has an irssi client running for me constantly through tmux. Connecting to the server, and typing "tmux attach" works fine and everything works ...