Using NVM node version confusion when installing Tilestream

Question

I am having difficulties installing Tilestream. I follow the instructions listed here (https://github.com/mapbox/tilestream) for Ubuntu 10.04 which I am running. I receive the following error:

npm WARN engine tilestream@1.0.0: wanted: {"node":"0.4.x"} (current: {"node":"0.8.5","npm":"1.1.46"})
npm ERR! error rolling back Error: EACCES, unlink '/usr/bin/tilestream'
npm ERR! error rolling back  tilestream@1.0.0 { [Error: EACCES, unlink '/usr/bin/tilestream'] errno: 3, code: 'EACCES', path: '/usr/bin/tilestream' }
npm ERR! Error: EACCES, unlink '/usr/bin/tilestream'
npm ERR!  { [Error: EACCES, unlink '/usr/bin/tilestream'] errno: 3, code: 'EACCES', path: '/usr/bin/tilestream' }
npm ERR!
npm ERR! Please try running this command again as root/Administrator.

npm ERR! System Linux 2.6.18-274.7.1.el5.028stab095.1
npm ERR! command "nodejs" "/usr/bin/npm" "install" "-g" "tilestream"
npm ERR! cwd /home/ben
npm ERR! node -v v0.8.5
npm ERR! npm -v 1.1.46
npm ERR! path /usr/bin/tilestream
npm ERR! code EACCES
npm ERR! errno 3
npm ERR! stack Error: EACCES, unlink '/usr/bin/tilestream'
npm ERR!
npm ERR! Additional logging details can be found in:
npm ERR!     /home/ben/npm-debug.log
npm ERR! not ok code 0

Running node --version gives v0.4.9 but the error log says I am using version 0.8.5! I use nvm but did install node from their website before I realised I needed an older version. I tried to uninstall it but it may not have disappeared completely?

When I run with sudo it does install but with errors and doesnt work. Even if I manually install all the modules it requires as suggested in troubleshooting I end up with 'Cannot read property 'userAgent' of undefined' error.

I really think I need to get it finding the right version of node. How do I do this?

Thanks