apt sources.list: inconsistency between sarge and stable

[kurt kuene <kurtkuene@gmx.net>]

hi

i run sarge.
there were the php4 (and more) security updates recently.

#---
my /etc/apt/sources.list contains this line:
deb http://security.debian.org/ sarge/updates main contrib non-free
--
now when i make:
apt-get update
apt-get upgrade
it will make the courier upgrade but not the php4 php4-mysql etc. upgrades.

#---
if i change the line in my /etc/apt/sources.list to:
deb http://security.debian.org/ stable/updates main contrib non-free
--
it will make all upgrades!

why is this inconsistency?
i think this is rather dangerous. i noticed it only by chance!
otherwise i would not have all updates!

so what is the difference in the apt sources.list between "sarge" and "stable"?

regards
kuene