I use Escq a lot (stashing the current line while I execute another command), and it works fine with Gnome Terminal 3.6.0 + zsh. However, if I start tmux, then it stops working: the cursor just moves one character to the left and stays there. Altq does not work either.
I don't set TERM in .zshrc, in .tmux.conf I use: set -g default-terminal "screen-256color".
I found out a solution for myself (Alt-q)
bindkey "^[q" push-line I got that "^[" part from the zkbd script (see man zshcontrib). You probably can get the equivalent for the ESC key there, but it looks to be the same.
It doesn't work because tmux decides it is an escape sequence that ought to match one of the keys defined in your terminal description (terminfo), but fails to find a match and discards it.
