Ubuntu

Comment 5 for bug 865266

Here's a ppa that you can test it out. It's for the new beta release and there are bugs related to the beta, but if you can try out the ethernet library (I don't have that shield)

https://launchpad.net/~showard314/+archive/ppa

It's committed to the debian repo. When Arduino releases version 1.0, we'll upload the new version and fix.