Not importing after table prefix change

I recently changed my WordPress table prefix, and I followed this guide here:

http://www.wpbeginner.com/wp-tutorials/how-to-change-the-wordpress-database-prefix-to-improve-security/

Now when I try to import a few pages I exported from another WordPress blog (same 3.7.1 version) the file gets uploaded correctly, I am correctly prompted to choose a local user to assign all the imported pages but when I click ‘Submit’, it stops/works for a while and then it logs me out of my account into the wp-login page and my content doesn’t get imported.

Might be helpful to mention that the WordPress blog I exported from still uses the ‘wp_’ table prefix. Which is different from the one in my new blog. Any ideas on how to fix this?

http://wordpress.org/plugins/wordpress-importer/