[CentOS] a-gnome-oyences

Most of my users are on kde, as am I (I really don't like gnome). I've got
one on gnome, though, CentOS 6.4, and I have a problem: I have to start an
agent running ->on login<-, so that the same one is in the environment of
every term window he opens. In kde, no problem, I modify
/etc/X11/xinit/xinitrc-common so that code in there calls our (newer)
ssh-agent instead of the stock one. (And, of course, it's killed on
logout, and there's only one running, not one every time that never go
away unless killed manually.)

/etc/gdm/Xsession *says* that it sources that file, so it should be
running when he logs in. I've just had him log out and log back in,
<ctl><alt><bkspc>, and no matter what, it just ain't running.

So, gnome fans, how do I get that to work? Edit /etc/gdm/custom.conf? Edit
something else? gconftool-2 (gahhhh)?

       mark