apt-get update fails

[valies]

I am running Debian Lenny on a server and on a router, both in VMware.

When running apt-get update, he can't connect to the mirrors. The strange thing is that it worked before with these mirrors.

sources.list (server)
#http, ftp
deb http://security.debian.org/ stable/updates main contrib
deb ftp://ftp.be.debian.org/debian/ stable main

interfaces (server)
#the loopback network interface
auto lo
iface lo inet loopback

#the primary network interface
auto eth0
iface eth0 inet static
address 192.168.0.3
gateway 192.168.0.1
netmask 255.255.255.224
network 192.168.0.0
broadcast 192.168.0.31

192.168.0.1 is the router's internal ip address, the external is connected with the host that is running VMware (dhcp). I can ping internet websites from the router as well as the server. So why can't I update apt? I have been searching all over the internet and tried some solutions, but they do not work... I'm hoping you guys can help me out