Getting DynamoDB working from Erlang-Collection of common programming errors

I am trying to use the Erlang ddb module to interface with amazon’s DynamoDB and I am getting a strange error while trying to set things up. I call ddb_iam:credentials() and it returns ‘ok’, but the ddb_iam:token() function crashes with an error as such: (this example is taken right from the manual page.

ddb_iam:credentials(AccessKey, SecretKey).
{ok, Key, Secret, Token} = ddb_iam:token(129600).
** exception error: bad argument
     in function  ets:lookup/2
        called as ets:lookup(ibrowse_lb,{"sts.amazonaws.com",443})
     in call from ibrowse:send_req/6 (src/ibrowse.erl, line 313)
     in call from ddb_aws:retry/4 (src/ddb_aws.erl, line 50)
     in call from ddb_iam:token/1 (src/ddb_iam.erl, line 63)
8>