apt-get cannot conect to server

[oxy <oxyopes@googlemail.com>]

Hi all,
 similar posts around refer to wrong proxy configuration, wrong
 /etc/apt/sources.list files etc. None seems to be my case. Look:

# apt-get update
Err http://security.debian.org etch/updates Release.gpg
  Could not connect to security.debian.org:80 (1.0.0.0), connection timed out
Err http://download.virtualbox.org etch Release.gpg
  Could not connect to download.virtualbox.org:80 (1.0.0.0),
connection timed out
Err http://ftp.de.debian.org etch Release.gpg
  Could not connect to ftp.de.debian.org:80 (1.0.0.0), connection timed out
Failed to fetch http://ftp.de.debian.org/debian/dists/etch/Release.gpg
 Could not connect to ftp.de.debian.org:80 (1.0.0.0), connection timed
out
Failed to fetch
http://security.debian.org/dists/etch/updates/Release.gpg  Could not
connect to security.debian.org:80 (1.0.0.0), connection timed out
Failed to fetch
http://download.virtualbox.org/virtualbox/debian/dists/etch/Release.gpg
 Could not connect to download.virtualbox.org:80 (1.0.0.0), connection
timed out
Reading package lists... Done
E: Some index files failed to download, they have been ignored, or old
ones used instead.

Its a debian etch connected to internet and resolving names, having
the following /etc/apt/sources.list file:

deb http://ftp.de.debian.org/debian/ etch main contrib non-free
deb-src http://ftp.de.debian.org/debian/ etch main contrib non-free

deb http://security.debian.org/ etch/updates main contrib non-free
deb-src http://security.debian.org/ etch/updates main contrib non-free
deb http://download.virtualbox.org/virtualbox/debian etch non-free

My apt-get:

# apt-get --version
apt 0.6.46.4-0.1 for linux i386 compiled on Feb 26 2007 16:19:57
Supported modules:
*Ver: Standard .deb
*Pkg:  Debian dpkg interface (Priority 30)
 S.L: 'deb' Standard Debian binary tree
 S.L: 'deb-src' Standard Debian source tree
 Idx: Debian Source Index
 Idx: Debian Package Index
 Idx: Debian dpkg status file

The only major change i've done lately is to conect to different networks
 using different host/domain names. (seems no real reason for problems)

 I have no /etc/apt/apt.conf or /etc/apt/preferences file in my system.

 Any help? Thanx in advance ...