Subscribe By Email Not working on certain sites in Multisite setup

I am having an issue where certain sites in a multi-site setup are not getting the "Subscribe By Email" plugin to accept emails. The sites in question have the widget and people can visit and enter their emails. They even get the "success" prompt, but in the admin panel there are no emails listed.

Here is one example:

I have added the plugin to the MU folder so that every site has it. I should also mention I am using Buddypress as well. I am also using the Blog Templates plugin and a few others from the website here.

Thanks for any help you might be able to provide,