So no - nothing to do with styling. Here's what happens.
I activate the plugin, set the options, and then go to configuration where I put in my mailchimp API key and choose what list to sent people to, click save, etc... Then - when I check right after, the comment forms and registration forms do have the opt-in box as it should. However, several hours later, Ill come back and notice that the checkbox is no longer on the forms. So, Ill go back to the configuration and it will then be reset showing that mailchimp was not activated. So, Ill go in and re-input the API key, etc... get it working again, and then check the next day, and it's gone again.
So, Im not sure what's causing this, but Im thinking perhaps it's a plugin conflict. unfortunately, I cant seem to find which plugin might be doing this but overall, the problem is that the information in configuration for mailchimp keeps getting wiped out.
BTW - thanks for the support. I really appreciate it as most of the time plugin developers that I've emailed dont respond, so I really appreciate the help.