apt-get – problem configuring /etc/apt/sources.list

[Vwaju <lou@manhattanhandyman.com>]

With a little help from my friends, I'm teaching myself networking by
building an internet server.  I am running Debian Linux 3.1 on a Dell
Dimension 4100 desktop.

I have installed ISPConfig, and I now I'm trying to install monit:

# apt-get install monit

Reading Package Lists...
Building Dependency Tree...
The following NEW packages will be installed:
  monit
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 228kB of archives.
After unpacking 643kB of additional disk space will be used.
Get:1 ftp://ftp.us.debian.org oldstable/main monit 1:4.5-1 [228kB]
Err ftp://ftp.us.debian.org oldstable/main monit 1:4.5-1
  Unable to fetch file, server said 'Failed to open file.  ' [IP:
35.9.37.225 21]
Failed to fetch ftp://ftp.us.debian.org/debian/pool/main/m/monit/monit_4.5-1_i386.deb
Unable to fetch file, server said 'Failed to open file.  ' [IP:
35.9.37.225 21]
E: Unable to fetch some archives, maybe run apt-get update or try with
--fix-missing?

I tried the update and –-fix-missing options, which don't help.

Here is /etc/apt/sources.list:
- - - - - - - - - - - - - - - - - - - - - - - - -
#deb file:///cdrom/ sarge main

deb ftp://ftp.us.debian.org/debian/ oldstable main
deb-src ftp://ftp.us.debian.org/debian/ oldstable main

#added by me 11/19/08
#doesn't work!
#deb http://sunsite.mff.cuni.cz/MIRRORS/ oldstable main

deb http://security.debian.org/ oldstable/updates main
- - - - - - - - - - - - - - - - - - - - - - - - -

The man pages for apt-get and for sources.list are kind of hard to
understand.  I googled monit_4.5-1_i386.deb, and found it at:
http://sunsite.mff.cuni.cz/MIRRORS/ftp.debian.org/debian/pool/main/m/monit
/

I tried to insert a line in sources.list, but it doesn't work (see
line added 11/19/08, then commented out).

What does the entry in sources.list needs to look like in order to
download monit_4.5-1_i386.deb?

Best Regards,
Vwaju
New York City