Puppet AWS basic issue

[Ghh]

Experts:

I have set up the AWS key id and access key in .fog file

while I run some basic commands like

 puppet node_aws list -region=us-west-2

I get no outputs of the EC2 instances , just comes back to the prompt, but  I am running already


now When I execute the same command, I  get the error message

Error: AuthFailure => AWS was not able to validate the provided access credentials
Error: Try 'puppet help node_aws list' for usage


My network is working and I have not touched the .fog file or it was not updated by any program

Please help,

Thanks

[Ghh]

any pointers? please.....