Salam (means Hello) :)
I have the latest version of node.js installed on ubuntu 12.04, I\'m not behind any proxies, and my network settings are correctly configured,
I was having the same problem. Found a solution in this thread. You can see the effective proxy that npm is using by doing:
npm
npm config get proxy npm config get https-proxy
If you're behinid a proxy, try this:
mv ~/.npmrc ~/.npmrc.bak