Servers may be currently down or very slow due to the big load created by Intrepid Ibex (Ubuntu 8.10) downloads.
You should download using BitTorrent, to both get better download speed and lightening the load on the servers.
BitTorrent links for the most downloaded variants of Ubuntu can be found at:
Torrents for other variants are at http://nl.releases.ubuntu.com/8.10/
If you're already on Ubuntu, you have a BitTorrent client installed, so just download the .torrent files and click on them.
See this for a list of clients also for other operating systems.
At http://hr.releases.ubuntu.com/8.10/ you will find files that end with a .metalink extension.
These will let you download Ubuntu from several mirrors concurrently, and are recommended if you cannot use torrents.
Download the .metalink file you need, then use any method to install the "aria2" package. Then type:
in a terminal to download Ubuntu.
You can find more information on Metalink, and clients for other operating systems, at the Metalinker site.
Avoid using HTTP downloads if you use the above methods.
There is a list of mirrors to download Ubuntu from using HTTP - for instance, you could use http://fr.releases.ubuntu.com/8.10/
The DVD images are available as torrents, but they can be downloaded via HTTP if absolutely necessary from several mirrors, for example http://ftp.acc.umu.se/mirror/cdimage.ubuntu.com/releases/8.10/release/