WordPress import won't work


I have installed yootheme – Enterprise with the demo setup. I delete all demo posts, pages, cats, tags and I am trying to import posts,categories,etc from my old blog. The import runs, gives me a successful message with no error. But when I go to posts,pages I see the demo content is fully restored and none of my imported stuff is there.

Any ideas why is it happening? Is that a permission issue or I need to disable/enable some theme settings?

I have also noticed that it is not only the content that is reset. All WP settings revert back to the default demo state: widgets I changed, general wp settings all back to demo.