为什么NPM无法在Ubuntu上安装Socket.io？

我已经有VMPlayer在Win7上运行Ubuntu v11.04。 我刚完成了NodeJS v0.5.4-pre和NPM v1.0.22的全新安装。 当试图安装Socket.io，我得到这个：

ohad@ubuntu:~$ sudo npm install socket.io npm ERR! registry error parsing json npm ERR! SyntaxError: Unexpected token H npm ERR! Host not found npm ERR! at Object.parse (native) npm ERR! at IncomingMessage.<anonymous> (/usr/local/lib/node_modules/npm/lib/utils/npm-registry-client/request.js:167:25) npm ERR! at IncomingMessage.emit (events.js:88:20) npm ERR! at HTTPParser.onMessageComplete (http2.js:133:23) npm ERR! at CleartextStream.ondata (http2.js:1095:22) npm ERR! at CleartextStream._push (tls.js:328:27) npm ERR! at SecurePair.cycle (tls.js:617:20) npm ERR! at EncryptedStream.write (tls.js:121:13) npm ERR! at Socket.ondata (stream.js:36:26) npm ERR! at Socket.emit (events.js:67:17) npm ERR! Report this *entire* log at: npm ERR! <http://github.com/isaacs/npm/issues> npm ERR! or email it to: npm ERR! <[email protected]> npm ERR! npm ERR! System Linux 2.6.38-10-generic npm ERR! command "node" "/usr/local/bin/npm" "install" "socket.io" npm ERR! cwd /home/ohad npm ERR! node -v v0.5.4-pre npm ERR! npm -v 1.0.22 npm ERR! npm ERR! Additional logging details can be found in: npm ERR! /home/ohad/npm-debug.log npm not ok 

有任何想法吗？