npm module installed but not available?

I implemented a npm module (called wrench) in an application which I always tested locally. That worked always without problems. Then I was trying to install wrench on my server.

npm install wrench did work as expected but as soon as it comes to require("wrench"), I get the following error:

> require("wrench")
Error: Cannot find module 'wrench'
    at Function._resolveFilename (module.js:320:11)
    at Function._load (module.js:266:25)
    at require (module.js:348:19)
    at [object Context]:1:1
    at Interface.<anonymous> (repl.js:171:22)
    at Interface.emit (events.js:64:17)
    at Interface._onLine (readline.js:153:10)
    at Interface._line (readline.js:408:8)
    at Interface._ttyWrite (readline.js:585:14)
    at ReadStream.<anonymous> (readline.js:73:12)

If I run npm ls I can see

wrench@0.1.0

Is there something I am missing here?

Thanks,

Elias

I believe npm ls shows all the the packages available on npm. To see the installed packages I think you should issue npm ls installed.

I have:

alfred@alfred-laptop:~$ node -v
v0.4.1

alfred@alfred-laptop:~$ npm --version
0.2.17

I issue:

alfred@alfred-laptop:~$ npm install wrench
npm info it worked if it ends with ok
npm info using npm@0.2.17
npm info using node@v0.4.1
npm info fetch http://registry.npmjs.org/wrench/-/wrench-0.1.0.tgz
npm info calculating sha1 /home/alfred/local/lib/node/.npm/nvm/0.0.6/package/v0.4.1/lib/node/.npm/.cache/wrench/0.1.0/package.tgz
npm info shasum 07440ad670068e0e81c8126c4641d1ca73b83557
npm info preinstall wrench@0.1.0
npm info install wrench@0.1.0
npm info postinstall wrench@0.1.0
npm info preactivate wrench@0.1.0
npm info activate wrench@0.1.0
npm info postactivate wrench@0.1.0
npm info build Success: wrench@0.1.0
npm ok

alfred@alfred-laptop:~$ node
> require('wrench')
{ rmdirSyncRecursive: [Function],
  copyDirSyncRecursive: [Function],
  chmodSyncRecursive: [Function] }
>

My advice is to use the latest and greatest npm and node.js and try again.