My version of node is always v0.6.1-pre even after I install brew node and NVM install v0.6.19.
My node version is:
If you're unable to locate node just run whereis node and whereis npm and whereis nvm and you can remove the listed directories as needed.
whereis node
whereis npm
whereis nvm
You'll also need to entirely close your terminal and reopen it for changes to take effect.