sources.list says my Sarge is unstable

["Alexandre Irrthum" <Alexandre.Irrthum@icr.ac.uk>]

Hi,

I'm discovering Debian and just installed Debian 3.1 r0a (Sarge). The
/etc/apt/sources.list file confuses me. Why are the cdrom sources marked
as unstable if Sarge is now stable ? Why is the first line commented out
? Is the last line, added by me, OK, or is it better to put
sarge/updates instead of stable/updates ?

Thanks for your help,

alex 

P.S. Please CC answer to me if possible as I've not subscibed to the
list.

------------------------
#deb file:///cdrom/ sarge main

deb cdrom:[Debian GNU/Linux 3.1 r0a _Sarge_ - Official i386 Binary-5
(20050607)]/ unstable contrib main
deb cdrom:[Debian GNU/Linux 3.1 r0a _Sarge_ - Official i386 Binary-4
(20050607)]/ unstable contrib main
deb cdrom:[Debian GNU/Linux 3.1 r0a _Sarge_ - Official i386 Binary-3
(20050607)]/ unstable contrib main
deb cdrom:[Debian GNU/Linux 3.1 r0a _Sarge_ - Official i386 Binary-2
(20050607)]/ unstable contrib main
deb cdrom:[Debian GNU/Linux 3.1 r0a _Sarge_ - Official i386 Binary-1
(20050607)]/ unstable contrib main

deb http://security.debian.org/ stable/updates main contrib non-free
----------------------

Alexandre Irrthum, Ph.D.
Section of Cancer Genetics
Brookes Lawley Building
Institute of Cancer Research
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Sutton Surrey
SM2 5NG UK

Tel +44 (0)208 722 4000 - ext 4729
Fax +44 (0)208 722 4359