grunt grunt-s3 upload error ECONNREFUSED issue

I am using grunt to do a build and one plugin I am using is grunt-s3 to push files (if tests successful) to the cloud.

However, I am getting:

Running "s3" task

>> Error: Upload error: /header/dist/js/lib/json2.min.js.gz (Error: connect ECONNREFUSED)
>> Error: Upload error: /header/dist/js/lib/modernizr.custom.js.gz (Error: connect ECONNREFUSED)
>> Error: Upload error: /header/dist/js/master.menu.min.js.gz (Error: connect ECONNREFUSED)

Anyone have any idea what I can check/change? My Amazon credentials are ok as I can log in using my key/secret to my bucket via cloudberry explorer on the same machine/connection so must be something node/grunt related?

EDIT

Reading npm docs says this:

"I get ECONNREFUSED a lot. What's up?

... or node's DNS isn't able to reach out."

This sounds intriguing, but I have no idea what to check or how to resolve as I am new to node.js