MailChimp Confirmation Email Being Sent Intermittently

Hi,

I have created a GF sign-up form and I'm using the MailChimp add-on to add subscribers to my MC list. I use a unique email every time I submit the form for testing. GF is receiving the entries just fine. The only time I can see when MailChimp successfully sends a confirmation email is when I've entered information to every field (check every box and enter address for both requried and non-required fields). This form NEEDS to work if only 1 checkbox is marked ("sign me up for emails").

I have tried creating groups like this post suggested:
http://www.gravityhelp.com/forums/topic/mailchimp-not-getting-subscribers?replies=6#post-70001

I'm using the latest GF 1.6.7 and MailChimp 1.7. I've also tried GF 1.6.2 and MailChimp 1.5. Some people suggested downgrading to GF 1.6 but that didn't work for me:
http://www.gravityhelp.com/forums/topic/mailchimp-not-getting-subscribers#post-69279

Once the confirmation email is sent, the user gets added to the MC list just fine.

Why is the only way my form works is when all fields are filled out?

I am having an issue with Gravity Forms not sending to Mailchimp. The form works when I submit from Preview, but not from the actual webpage... what gives?

I have 3 forms on the site. 2 work just fine and send submissions to Mailchimp. One doesn't... the one that doesn't work has a number of form options and filters for multiple mailchimp groups...

It seems the simple forms go through without a problem, but not the one I really need to go to mailchimp.

@chris, the GF does not appear when I view it in Preview. That's probably not a good thing. I'll look more into why this is happening. Any ideas off the top of your head?

@chris, I finally figured it out. In MC, there was a field that was required unnecessarily. I "un-required" it and the form started behaving as expected. I was able to set up my conditional fields and everything else I wanted.

Thanks