WordPress Plug-In problem

Dear All

I have just installed the mailchimp plug-in which is used for integrating the mail subscription systen with the WordPress site.

Version 0.8.6
Plug-In address: https://github.com/kalchas/MailChimp-Widget

But when i tried to activate it, it gives “fatal error” . Could anyone help me to activate and use it in my site ?

My wordpress edition is 3.1.3

Thanks