Wow, 5 years later I have same problem and no solution yet, should have read this before choosing dating script.
The issues you're facing might be down to your php handler. You have previously stated that you're using an shared server that runs PHP as suPHP, not apache module.
it has been mentioned before by maverick that it can possibly cause some issues
PHP as a CGI mod and enabling suPHP that can cause issues or hinder some functions. It's possible to configure PHP CGI and suPHP to work ok with Etano if the host is willing to do it, but many won't.
Do you get any errors in your error log in the admin panel or any other logs you access to?
Are all your folder/file permissions correct?
On a SuPHP system permissions on folders should be chmod 755 and files should be 644
Maybe try using database sessions instead?