Hi, virginiabonora,
That is strange I tested the case and it is working with my installation and that is your installation which has such a problem.
I do suggest that you start from scratch. Please use the WP Reset plugin to reset your WordPress installation (You will lose all your data) and start over.
I also went to Settings > General and turned off the Endurance Cache as it might cause issues when impoting the demo content.
I also installed the wp serverinfo plugin and if you go to Dashboard > WP-ServerInfo you will see your server information. YOu need to change the settings below:
- PHP Memory Limit: It is 256 for you, you should increase it to 512. Please read this article for more information.
- PHP Max Script Execute Time: It is 30 for you, it should be 300. Contact your hosting service provider for more information.
Thank you.