Hi Avni,
Ubuntu 8.04 LTS is no longer being supported by the ubuntu guys, so it doesn't make sense to support the old 8.04 openacs packages. That's why I updated the wiki pages with information about installing on ubuntu 10.04, the current LTS version.
If you really need it, i think i could find the old packages and dependencies needed for ubuntu 8.04, but I strongly suggest you to update to 10.04.
Cheers, Héctor