Duplicity, amazon s3 backend exception

I'm trying to create an auto backup using duplicity into amazon s3 following this guide: easy server backups to amazon s3 with duplicity However, at this command: ``` duplicity /var/www s3+http://com.mycorp.myhost.backup ``` I encounter the error: ``` BackendException: Could not initialize backend: No module named boot ``` Googling does not yield understandable results for me. FYI, the actual command I run is: ``` duplicity /Users/okyretina/Dropbox/archive/ s3+http://com.sinkdrive.okyretina.dropbox.archieve ``` I understand that this guide is for linux and I am using mac osx lion but I figured it should work as well. Any help is appreciated. Thanks.