My terminal setup is gnome-terminal + tmux + zsh with vi bindings.
In applications like vim or even in the zsh's command line vi editing mode, I need to frequently hit the ESC key but there is a small delay before the effects of this key take place. See GNU Screen makes Vim ESC key slow
After some experimentation, I found that hitting ESC key and immediately another key (say b) has the same effect as hitting Alt+b. I don't know why this is the case (probably for legacy reasons when there was no Alt? I don't know). Either way, I have two Alt keys and I don't want this behaviour with my ESC key. I have tried with C+[ and its the same problem with that too.
I'm not sure who is responsible for this, gnome-terminal or tmux or my OS itself (Ubuntu Natty). Any ideas on how to address this would be great.
Update: I checked without tmux on a different terminal (LXTerminal) and the delay is present there too.