I've been getting a number of emails to say their poll isn't working; about 80% of these are issues caused by the theme file missing the wp_footer(). It's an important function to add to your theme (in the footer.php file) not just for Simply Poll but a number of other plugins and possibly WordPress.
So, if you are getting issues where the poll isn't being submitted, then please check that your theme has wp_footer(), if you do then feel free to comment on the forum here, GitHub or mailing me directly.
Hopefully this will speed up any debugging for you.
Thanks! ^_^