Well I thought I would post this after my experience setting up the Nucore setup for my RFM. I was going to post this to Nucore bulletin board, but I can't get access to it, so I will post it here.
A little background, I purchased my RFM from one a container deal and it works 100% with the factory computer, but when it was announced that Nucore was being discontinued I decided I should probably grab it up. I liked the idea of the configuration for ignoring LED's in the self test, using modern non-proprietary hardware and the jukebox function.
Fast forward to last week, I finally decided to put all the pieces together and set my system up and test everything. Set the computer up on the bench and installed Ubuntu 8.04LTS and finally managed to get my network adapter to work in Ubuntu and then discovered that 8.04LTS has reached End Of Life as of May 9,2013 and now the standard repositories no longer exist. This leaves you with a bit of a dilemma if you need to re-do your Nucore setup, or like me, you have had your Nucore sitting on a shelf waiting until you get around to setting it up.
However there is a workaround. Unfortunately I don't know how long this workaround will work, so I would highly recommend if you haven't set up your Nucore up yet, do it now.
What you will need to do is follow the instructions on the following website to update your sources.list file to include a new repository that has the files for the obsolete Ubuntu versions.
If you don't have all the files downloaded that you need, you may have to dig around, the nucore.tar.tar file is no longer available at the link posted. I thankfully already had it downloaded, but there may be a workaround. This is something that is a subject for someone smarter than I.
Hopefully this helps some people out. My recommendation is that if you haven't set your system up yet, do it as soon as possible. If you do have yours set up and working, back it up!