Re: WordPress Petition Plugin
I’m afraid if the developer of that plugin is not responding to your questions, then that may very well indicate that they have stopped supporting the plugin. You should post (if you have not already) on the WPMU forums and see if anyone has information.
Perhaps someone there may know of an alternative or will adopt the plugin and bring it up to code. Make sure you mention that you want to use this plugin in BuddyPress.