Running `npm outdated -g` shows everything outdated (even though it's not)

gistfile1.sh

$ npm outdated -g
npm http GET https://registry.npmjs.org/c-pm
npm http GET https://registry.npmjs.org/bugger
npm http GET https://registry.npmjs.org/buffet
npm http GET https://registry.npmjs.org/coffee-script
npm http GET https://registry.npmjs.org/froth
npm http GET https://registry.npmjs.org/ecstatic
npm http GET https://registry.npmjs.org/gh
npm http GET https://registry.npmjs.org/jshint
npm http GET https://registry.npmjs.org/express
npm http GET https://registry.npmjs.org/jsonlint
npm http GET https://registry.npmjs.org/madge
npm http GET https://registry.npmjs.org/node-dependencies
npm http GET https://registry.npmjs.org/n
npm http GET https://registry.npmjs.org/replace
npm http GET https://registry.npmjs.org/police
npm http GET https://registry.npmjs.org/jsontool
npm http GET https://registry.npmjs.org/testling
npm http GET https://registry.npmjs.org/travisify
npm http GET https://registry.npmjs.org/st
npm http GET https://registry.npmjs.org/npm
npm http 304 https://registry.npmjs.org/froth
npm http 304 https://registry.npmjs.org/c-pm
npm http 304 https://registry.npmjs.org/bugger
npm http 304 https://registry.npmjs.org/buffet
npm http 304 https://registry.npmjs.org/coffee-script
npm http 304 https://registry.npmjs.org/ecstatic
npm http 304 https://registry.npmjs.org/gh
npm http 304 https://registry.npmjs.org/jshint
npm http 304 https://registry.npmjs.org/express
npm http 304 https://registry.npmjs.org/madge
npm http 304 https://registry.npmjs.org/jsonlint
npm http 304 https://registry.npmjs.org/node-dependencies
npm http 304 https://registry.npmjs.org/n
npm http 304 https://registry.npmjs.org/police
npm http 304 https://registry.npmjs.org/testling
npm http 304 https://registry.npmjs.org/replace
npm http 304 https://registry.npmjs.org/jsontool
npm http 304 https://registry.npmjs.org/travisify
npm http 304 https://registry.npmjs.org/st
npm http 304 https://registry.npmjs.org/npm
[email protected] /usr/local/lib/node_modules/froth current=0.0.5
[email protected] /usr/local/lib/node_modules/c-pm current=0.0.3
[email protected] /usr/local/lib/node_modules/bugger current=0.5.1
[email protected] /usr/local/lib/node_modules/buffet current=0.6.0
[email protected] /usr/local/lib/node_modules/coffee-script current=1.6.3
[email protected] /usr/local/lib/node_modules/ecstatic current=0.4.7
[email protected] /usr/local/lib/node_modules/gh current=1.2.2
[email protected] /usr/local/lib/node_modules/jshint current=2.1.10
[email protected] /usr/local/lib/node_modules/express current=3.3.5
[email protected] /usr/local/lib/node_modules/madge current=0.1.4
[email protected] /usr/local/lib/node_modules/jsonlint current=1.6.0
[email protected] /usr/local/lib/node_modules/node-dependencies current=0.3.1
[email protected] /usr/local/lib/node_modules/n current=1.1.0
[email protected] /usr/local/lib/node_modules/police current=0.3.2
[email protected] /usr/local/lib/node_modules/testling current=1.5.1
[email protected] /usr/local/lib/node_modules/replace current=0.2.7
[email protected] /usr/local/lib/node_modules/jsontool current=6.0.0
[email protected] /usr/local/lib/node_modules/travisify current=0.1.9
[email protected] /usr/local/lib/node_modules/st current=0.2.1
[email protected] /usr/local/lib/node_modules/npm current=1.3.8

$ npm --version
1.3.8

$ which npm
/usr/local/bin/npm

$ node --version
v0.10.17

$ which node
/usr/local/bin/node

Note that every installed "outdated" package has the same version as "current" - so nothing is actually outdated - but npm outdated is displaying it as such.

Unless this is expected behaviour now? Will an actual outdated module display something different?