My linux system used to install a old version node.js environment 0.8.14, now updated it to latest node.js through this
sudo apt-get install python-software-
I'm willing to bet you installed the previous version through apt-get
without first adding Chris Lea's PPA. The standard Ubuntu repositories have an old version of node.
You'll need to uninstall this old version before you can get the new one:
sudo apt-get --purge remove nodejs # Remove the package itself
sudo apt-get autoremove # Remove any unneeded dependencies
sudo apt-get update
sudo apt-get install nodejs