I cloned the howtonode repo, but couldn't get it to work properly with the Node.JS version that ships with Ubuntu 12.04 - 0.6.10 or so. The index page loaded, but an (arbitrary) article did not. The server log was empty, and the client eventually timed out.
I tried to debug wheat with node-inspector for a little while, but couldn't really pinpoint the problem.
Upgrading Node to 0.8.8 fixed the problem.