S3 path doesn't support ~/.boto profiles.
If multiple credentials exits, many users have profiles in their ~/.boto as such- 

``` python
[profile Data-Robot]
aws_access_key_id = a key
aws_secret_access_key = a secret

[Credentials]
aws_access_key_id = default key
aws_secret_access_key = default secret
```

you can pass 

``````
In [70]: con = boto.connect_s3(profile_name="Data-Robot")
``` to load from a profile. However, you can not do this in pandas. 
``````
