So I've lived with this problem for several weeks now, hoping that if I just let it happen enough, I would figure out the underlying trigger. No luck.
tmux in bash in gnome-terminal in XMonad on Ubuntu 14.04.1 LTS (clean install). same bug in when instead of XMonad I use vanilla Unity (even clean installed).
It seems that every now and then something is printing the character u'0x001b', superimposed over a ']' character in the string "]112" instead of recognizing this as escape followed by some numbers, tmux prints it verbatim to a (random) position on the screen. Recently, the string "]112" has also started to appear without the unicode character very occasionally. It appears that if the characters go off the end of a vim line, replacing the first one can sometimes leave the others intact.
Anything that forces a redraw of the rectangle holding the unicode character gets rid of the whole sequence of them. In Vim, I can delete each individual character in the string "]112" as if it was actually there, however. Simply changinging their colors, e.g. by positioning the cursor over them in vim, does not get rid of them.
I don't have enough reputation to post images, but I'll host a little screencast of what the problem looks like at: http://www.brunobeltran.com/junkdump/tmux_error.mkv
Below is my .tmux.conf. I have played with various values for the escape-time, to no avail. Also, removing mouse stuff does not help.
Any idea or things to try would be greatly appreciated!
# 0 is too far from 1
set -g base-index 1
# Automatically set window title
set-window-option -g automatic-rename on
set-option -g set-titles on
set -g default-terminal screen-256color
set -g status-keys vi
set -g history-limit 10000
setw -g mode-keys vi
setw -g mode-mouse on
setw -g mouse-resize-pane on
setw -g mouse-select-pane on
setw -g mouse-select-window on
setw -g monitor-activity on
bind-key v split-window -h
bind-key s split-window -v
bind-key J resize-pane -D 5
bind-key K resize-pane -U 5
bind-key H resize-pane -L 5
bind-key L resize-pane -R 5
bind-key M-j resize-pane -D
bind-key M-k resize-pane -U
bind-key M-h resize-pane -L
bind-key M-l resize-pane -R
# Vim style pane selection
bind h select-pane -L
bind j select-pane -D
bind k select-pane -U
bind l select-pane -R
# Use Alt-vim keys without prefix key to switch panes
bind -n M-h select-pane -L
bind -n M-j select-pane -D
bind -n M-k select-pane -U
bind -n M-l select-pane -R
# Use Alt-arrow keys without prefix key to switch panes
bind -n M-Left select-pane -L
bind -n M-Right select-pane -R
bind -n M-Up select-pane -U
bind -n M-Down select-pane -D
# Shift arrow to switch windows
bind -n S-Left previous-window
bind -n S-Right next-window
# No delay for escape key press
set -sg escape-time 0
# copy to clipboard in sane way on linux with xclip
bind -t vi-copy y copy-pipe 'xclip -in -selection clipboard'
# Reload tmux config
bind r source-file ~/.tmux.conf
# THEME
set -g status-bg black
set -g status-fg white
set -g window-status-current-bg white
set -g window-status-current-fg black
set -g window-status-current-attr bold
set -g status-interval 60
set -g status-left-length 30
set -g status-left '#[fg=green](#S) #(whoami)'
set -g status-right '#[fg=yellow]#(cut -d " " -f 1-3 /proc/loadavg)#[default] #[fg=white]%H:%M#[default]'
## my additions start here
# fix pgup/pgdn issues
#set -ga terminal-overrides ',xterm*:smcup@:rmcup@'
# Set up workflow for CJW Lab
#
new -n Shell "/usr/bin/env bash"
splitw -h -p 50 -t 0 "bash"
neww -n Matlab "/opt/MATLAB/R2014b/bin/matlab -nodesktop -nosplash"
splitw -h -p 50 -t 0 "bash"
neww -n Mathematica "/opt/Wolfram/Mathematica/10.0/Executables/math"
splitw -h -p 50 -t 0 "bash"
neww -n Asciiquarium "~/bin/asciiquarium"
neww -n Media "/usr/bin/ncmpcpp"
# Fix my leader to be Ctrl-q
unbind-key C-b
set -g prefix 'C-q'
bind-key 'C-q' send-prefix
