dirtyx

Unfortunately I can’t. But I can explain my situation.
I have two widget areas, one for the sidebar of the page and one for the footer of the site.

Are all instances of your forms acting in this way or are any of them working without refreshing the page (like my content sidebar one)?

– Yes. Both refresh the page. Both react exactly the same on the submit. The error message is displayed in both forms after using any of them.

If you take a look in the source cod of the plugin you will see that there is a unique ID (#mc_signup_form) used for the form. That will clearly generate a problem because the Ajax will not know which of the forms has submitted the data for validation.