Mac OS X 10.8.4
Installed via homebrew.
command output: http://pastebin.com/88WUrNxT
Willing to assist in any way that I can.
Edit: added version and system information
http://pastebin.com/tZtVsW7G for the contents of the offending variables
Can you try with the latest version of npm? This was fixed in 1.3.9.
Yup, that did it. Sorry for the trouble. :)