tmux showing ^[[I^[[O when losing focus on ubuntu - vim

Question

I initially though this was a vim problem, but it seems like it is tmux problem.
I have executed and made the window lose focus and then regain it:
$ sleep 100
^[[I^[[O
$ echo $TERM
screen
Here are the options I tried
set mouse-utf8 off
set -g status-utf8 on
setw -g utf8 on
The consequence I see in vim
I have tested my vim with vim -u NONE, so I do not think this pertains to my .vimrc configuration. I also see this problem only on my Ubuntu machine and not my CentOS machine:
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=14.04
DISTRIB_CODENAME=trusty
DISTRIB_DESCRIPTION="Ubuntu 14.04.1 LTS"
NAME="Ubuntu"
VERSION="14.04.1 LTS, Trusty Tahr"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 14.04.1 LTS"
VERSION_ID="14.04"
HOME_URL="http://www.ubuntu.com/"
SUPPORT_URL="http://help.ubuntu.com/"
BUG_REPORT_URL="http://bugs.launchpad.net/ubuntu/"
Reproducing the issue for me simple. I just have to type something on any text click on another window (or C-TAB) and then come back to vim. I am attaching the screenshot.
I have tested the event with -V9 option and I see that s:TextChanged() is being triggered. Here is the output:
E349: No identifier under cursor
E39: No identifier under cursor
Type :quit<Enter> to exit Vim
1 line less; before #2 6 seconds ago
--No lines in buffer--
1: 2 afwefasdf
Type :quit<Enter> to exit Vim
1: 1 asdfjkq;wr
Is there a way for me silence it without affecting other plugins?
Here is my vim version:
vim --version
VIM - Vi IMproved 7.4 (2013 Aug 10, compiled Jan 2 2014 19:39:32)
Included patches: 1-52
Modified by pkg-vim-maintainers#lists.alioth.debian.org
Compiled by buildd#
Huge version without GUI. Features included (+) or not (-):
+acl +farsi +mouse_netterm +syntax
+arabic +file_in_path +mouse_sgr +tag_binary
+autocmd +find_in_path -mouse_sysmouse +tag_old_static
-balloon_eval +float +mouse_urxvt -tag_any_white
-browse +folding +mouse_xterm -tcl
++builtin_terms -footer +multi_byte +terminfo
+byte_offset +fork() +multi_lang +termresponse
+cindent +gettext -mzscheme +textobjects
-clientserver -hangul_input +netbeans_intg +title
-clipboard +iconv +path_extra -toolbar
+cmdline_compl +insert_expand -perl +user_commands
+cmdline_hist +jumplist +persistent_undo +vertsplit
+cmdline_info +keymap +postscript +virtualedit
+comments +langmap +printer +visual
+conceal +libcall +profile +visualextra
+cryptv +linebreak +python +viminfo
+cscope +lispindent -python3 +vreplace
+cursorbind +listcmds +quickfix +wildignore
+cursorshape +localmap +reltime +wildmenu
+dialog_con -lua +rightleft +windows
+diff +menu -ruby +writebackup
+digraphs +mksession +scrollbind -X11
-dnd +modify_fname +signs -xfontset
-ebcdic +mouse +smartindent -xim
+emacs_tags -mouseshape -sniff -xsmp
+eval +mouse_dec +startuptime -xterm_clipboard
+ex_extra +mouse_gpm +statusline -xterm_save
+extra_search -mouse_jsbterm -sun_workshop -xpm
system vimrc file: "$VIM/vimrc"
user vimrc file: "$HOME/.vimrc"
2nd user vimrc file: "~/.vim/vimrc"
user exrc file: "$HOME/.exrc"
fall-back for $VIM: "/usr/share/vim"
Compilation: gcc -c -I. -Iproto -DHAVE_CONFIG_H -g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=1
Linking: gcc -Wl,-Bsymbolic-functions -Wl,-z,relro -Wl,--as-needed -o vim -lm -ltinfo -lnsl -lselinux -lacl -lattr -lgpm -ldl -L/usr/lib/python2.7/config-x86_64-linux-gnu -lpython2.7 -lpthread -ldl -lutil -lm -Xlinker -export-dynamic -Wl,-O1 -Wl,-Bsymbolic-functions

Answer 1

Okay, after spending a half day on this problem. I have decided to just upgrade to tmux 1.9a from 1.8 and that fixed the problem. I don't know why, but CentOS was affected by 1.8.