hmm... I may not have the right answer for you, but I have some ideas you could try. but first, a few quick questions: What linus distro are you using? How did you install linux on this machine? You didn't install linux on that hard drive using another machine and then swap the hard drive to that machine, did you?
I have done that before, and it works pretty well, but it does tend to cause network issues because it is still looking for the old machines network interfaces (possibly causing an error like the one you are having). If that is the case, linux might have named your network card eth1 instead of eth0 but not enabled it, try bringing eth1 up (ifconfig eth1 up).
actually, thats all I can think of. I could be totally wrong, but that would be the first thing I would try.