Joomlamailer not working at all

joomlamailer version: 1.7.2
Joomla! version:1.7.3
PHP version: 5.3.6-7
MySQL version: 5.1.54

I just don't get it! Nothing is working.
I try to start a new campaign and I get "Table...."doesn't exist and more. Warning
Warning: Invalid argument supplied for foreach() in /home/users/pagedftp/pagedesign.nl/joomla/administrator/components/com_joomailermailchimpintegration/models/create.php on line 554. No saved drafts available. Please click on 'Create' and set up a draft first.
When i want to look a the email templates to change the templates I also get: You don't have permission to access /joomla/tmp/jleftcolumn/template.html on this server.
I have no idea what I'm doing wrong.
Do I need to do something in Mailchimp first?
Could you have a look? It's a testwebsite. Not a working website.
I can send info to login in to the website.
I like to use this for a client so I need to test it first.
Thanks, Marina