Can't find socket.io/socket.io.js

in firebug the following url is not found:
http://testcommons.dev:8181/socket.io/socket.io.js

how can I determine if nodejs is actually running?

npm ls
├─┬ express@2.5.11
│ ├─┬ connect@1.9.2
│ │ └── formidable@1.0.11
│ ├── mime@1.2.4
│ ├── mkdirp@0.3.0
│ └── qs@0.4.2
├── request@2.9.203
└─┬ socket.io@0.9.11
├── policyfile@0.0.4
├── redis@0.7.3
└─┬ socket.io-client@0.9.11
├─┬ active-x-obfuscator@0.0.1
│ └── zeparser@0.0.5
├── uglify-js@1.2.5
├─┬ ws@0.4.23
│ ├── commander@0.6.1
│ ├── options@0.0.3
│ └── tinycolor@0.0.1
└── xmlhttprequest@1.4.2

here is my config file:

settings = {
scheme: 'http',
port: 8181,
host: 'devserver',
resource: '/socket.io',
serviceKey: 'YourServiceKey',
backend: {
port: 80,
host: 'testcommons.dev',
scheme: 'http',
basePath: '',
messagePath: '/nodejs/message'
},
debug: false,
sslKeyPath: '',
sslCertPath: '',
baseAuthPath: '/nodejs/',
publishUrl: 'publish',
extensions: [],
clientsCanWriteToChannels: false,
clientsCanWriteToClients: false,
transports: ['websocket', 'flashsocket', 'htmlfile', 'xhr-polling', 'jsonp-polling'],
jsMinification: true,
jsEtag: true,
logLevel: 1
};