Proxy environment vars preventing connection with VM

General Discussions
1

On Win 7 on Docker Toolbox I created a VM named default using:
docker-machine create -d virtualbox default

When I run start.sh, I get:

                    ##         .
              ## ## ##        ==
           ## ## ## ## ##    ===
       /"""""""""""""""""\___/ ===
  ~~~ {~~ ~~~~ ~~~ ~~~~ ~~~ ~ /  ===- ~~~
       \______ o           __/
         \    \         __/
          \____\_______/

docker is configured to use the default machine with IP 192.168.99.100
For help getting started, check out the docs at https://docs.docker.com

Start interactive shell

$ docker images
An error occurred trying to connect: Get https://192.168.99.100:2376/v1.23/images/json: Service Unavailable

I exited the bash shell and removed the environment vars HTTP_PROXY and HTTPS_PROXY.

Then when I ran start.sh and docker images, the command worked fine.

How and why is the presence of the environment vars affecting the connection to the VM? How can I bypass it?

Thanks,
Yash