[CentOS] system environment variables

CentOS 3.x

Don't know how this got by me, but for
years I've been previously using /etc/profile
to set system wide environment variables and now
I just noticed it doesn't work any more (sort of).

If you log in via console it works,
log in via gdm, it does not, but use to work.

Now I noticed if I create script files
for the vars I want exported and include them
in /etc/profile.d/ the vars get set either way.

Is this now the correct way to set system
environment variables by using script files
in the /etc/profile.d/ ?????

Sorry, I couldn't find info on this, most
info says to use /etc/profile