Error using bees with machineguns

I have tried to use beeswithmachineguns for loadtesting a site but with little success. There is a similar post[link] (Bees with machine gun using Amazon free tier) but the error I receive is slightly different.

I use the following to start the bees.
bees up -s 1 -k Bees-West -g SWARM

The error I am getting is related to the groupId being empty but I am passing that value in with -g SWARM... or so I thought. My setup uses the us-west-2 region, which I have in my .boto file as noted in the linked post.

Connecting to the hive.
Attempting to call up 1 bees.
Traceback (most recent call last): File "/usr/local/bin/bees", line 5, in main.main()
File "/Library/Python/2.7/site-packages/beeswithmachineguns/main.py", line 127, in main parse_options()
File "/Library/Python/2.7/site-packages/beeswithmachineguns/main.py", line 111, in parse_options
bees.up(options.servers, options.group, options.zone, options.instance, options.login, options.key)
File "/Library/Python/2.7/site-packages/beeswithmachineguns/bees.py", line 104, in up
placement=zone) File "/Library/Python/2.7/site-packages/boto/ec2/connection.py", line 618, in run_instances
return self.get_object('RunInstances', params, Reservation, verb='POST')
File "/Library/Python/2.7/site-packages/boto/connection.py", line 699, in get_object
raise self.ResponseError(response.status, response.reason, body) boto.exception.EC2ResponseError: EC2ResponseError: 400 Bad Request
InvalidParameterValueValue () for parameter groupId is invalid. The value cannot be emptybd1c6bcb-875f-4294-af64-84853b5b258a