Environment: 

* Terminal Client
	+ pietty 0.4.0(beta 14) (which is forked from putty)
	+ putty 0.63
* OS & tmux version
	+ CentOS 6.5, tmux-1.6-3.el6.x86\_64
	+ ArchLinux, tmux 1.9\_a-1

Strange behavior:

* Split a vertical panel.
* It won't display a vertical line between left and right panels.
* When I click on right panels.
* It display a vertical line.

Is there any method to let it always display vertical line?

My tmux.conf

```
set -g utf8
setw -g utf8 on
set-option -g mode-mouse on
set-option -g mouse-resize-pane on
set-option -g mouse-select-pane on
set-option -g mouse-select-window on
# I've tried the following three settings, all failed.
set -g default-terminal "screen-256color"
#set -g terminal-overrides 'xterm*:smcup@:rmcup@'
#set -g default-terminal "linux"

```

And the TERM and locale variables inside tmux

```
$ echo $TERM
screen-256color
$ locale
LANG=en_US.utf8
LC_CTYPE=zh_TW.utf8

```