As written in handbook, you need to restart X in order to get X with updated variables (in /etc/profile.env)
Or to execute all commands in all terminals ...

But if I have executed the command in one terminal then logged out through another X window (not terminal) then logged in by startx... - no variables?
Maybe to try to logout only through the terminal in which I issued the command before. But after logging out - terminal perishes. - no env variables, too.

What did they meant?
I'm pretty unsure in those things and in which cases to issue env-update && source /etc/profile

1. if you set a variable in a login session, it only exists within that session and only until you logout of that session.
2. no need to source /etc/profile; it happens automatically as part of the login process

General refs/tutorials
http://rute.2038bug.com/index.html.gz
http://tldp.org/LDP/Bash-Beginners-G...tml/index.html
http://www.tldp.org/LDP/abs/html/

Login process
http://www.linuxjournal.com/article/3121
http://www.comptechdoc.org/os/linux/...x_hllogin.html

Have you set environmental variables in /etc/profile? and want to execute them after resarting for X windows... Right?