I solved it.
Node.js tools plugin on VIsual Studio suggested I upgrade it to the latest beta version. I innocently accepted and then started my problem.
I needed to remove the plugin and install the one suggested from http://nodejstools.codeplex.com/ to solve the problem.
You cannot remove it from the VS extension window (tools-> Extensions and updates) because it is an SO application, so you must remove it from the Control Panel-> uninstall programs.
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