Problem with the grunt.js file

Great work, only one issue, the grunt file provided with the example seems to have some problems.
At first I got a message complaining that concat is unknown.
After adding this line:
grunt.loadNpmTasks('grunt-contrib-concat');
I'm getting this error:
Warning: Unable to write "views/templates/compiled" file (Error code: EISDIR).
Could you please help?
