Check ‘Automatically append comments to articles?’ is set to ‘no’. More info.
Check you have the latest Textpattern language database update, new data was added to the Textpattern language server from 31/08/11 onwards specifically to support this theme. Go to the preferences, language tab – if you are not already running the latest language version there will be a prompt to update next to your installed languages. Click on ‘update’ and an up-to-date language table will be automatically loaded.