mailchimp form being stripped of code

I have a mailchimp form that I am adding to one of my pages using the editor.

Things work fine until I go back and edit the form or anything on the page.Or maybe it happens when I switch from the visual editor to the html editor, not sure. Once I do that WP strips out <!– Begin MailChimp Signup Form –> and the css link and <style> tags. Then I’m left with a form that has no more css etc associated with it.

Any way to avoid this?

iso

[No bumping, thank you.]