Can't get drex module to work

[aozora]

running app with: NODE_ENV=development node app.js
I get this:

module.js:340
throw err;
^
Error: Cannot find module 'drex'
at Function.Module._resolveFilename (module.js:338:15)
at Function.Module._load (module.js:280:25)
at Module.require (module.js:364:17)
at require (module.js:380:17)
at Object. (/Volumes/NAUSICAA/projects/arashin/lib/utils.js:13:12)
at Module._compile (module.js:456:26)
at Object.Module._extensions..js (module.js:474:10)
at Module.load (module.js:356:32)
at Function.Module._load (module.js:312:12)
at Module.require (module.js:364:17)

I did a npm install before in the app root directory, and the drex module seems to be installed in the node_modules dir.
I'm running Node 0.10.4 on a mac.