KOKON

It is a new tech. Reboot your pc 3 times in a row and your site would go even faster then that

lol i was so much sure that it is not my mistake.

it was like this in php.ini
;disable_functions = exec,passthru,shell_exec,system,proc_open,popen

so your debug is not debugging well ; )

p.s. i’m using ordinary apache 2

for cent os

yum install optipng
yum install gifsicle
yum install libjpeg

[root@xxx ~]# which optipng
/usr/bin/optipng
[root@xxx ~]# which jpegtran
/usr/bin/jpegtran
[root@xxx ~]# which gifsicle
/usr/bin/gifsicle

cent os
installed via
yum install optipng
yum install gifsicle
yum install libjpeg

The same problem here:
Debug information
computed jpegtran path: jpegtran
jpegtran location (using ‘which’):
computed optipng path: optipng
optipng location (using ‘which’):
optipng version:
computed gifsicle path: gifsicle
gifsicle location (using ‘which’):
gifsicle version:
safe mode: Off
Operating System: Linux
exec(): enabled
getimagesize(): OK
mime_content_type(): OK

15394 apache 15 0 57036 27m 5296 S 0.0 10.7 0:01.48 httpd

here is the place your filter is applied:
./wp-content/plugins/wordpress-seo/frontend/class-frontend.php

function title( $title, $sepinput = '-', $seplocation = '' ) {
..
..
    //var_dump($title);
    return esc_html( strip_tags( stripslashes( apply_filters('wpseo_title', $title ) ) ) );
}

my var_dump outputs $title with already stripped qTranslate tags

sfradel solution works for wpseo_metadesc
but not for wpseo_title
wp 3.4.1 WordPress SEO 1.2.7

p.s.: it looks like wpseo_title is already striptagged before suggested filter is applied