Hello,
I've exactly the same problem as this guy : http://www.gravityhelp.com/forums/topic/form-entries-not-saved#post-74405
I upgraded the new version of GF and now when people subscribes to my newsletter http://www.bebeconseils.fr/ i can't see the entries in the admin part, i receive an empty notification and the subscriber doesn't receive the optin email.
I have uninstall and reinstall GF 1.7, i have created a new form and a new list in mailchimp nothing change. I have tried other form where mailchimp is not setup and the problem is the same. I can't see the entries but the number is increasing and i receive an empty notification.
Thanks for your help