Assuming that:

a) It worked before,
b) All you changed is the software version installed on the empeg
c) You correctly installed Car2 software instead of accidentally installing Car1 software...

Then the problem is most likely a hardware one, or an external-to-the-empeg configuration issue.

One other user had a faulty ethernet adapter in his empeg, and it showed in the boot log. Can you give us a boot log?

Also, make sure you're plugging into a 10mbps hub instead of 100. The empeg doesn't do 100.

___________
Tony Fabris