Re: WordPress Petition Plugin
I have not seen anyone on the BuddyPress forums reporting that they are using this plugin. You are the first that I’ve seen.
From the error message, it looks like WPMU has an issue with some code in the plugin. It could be caused by another plugin you’ve installed being incompatible or simply a bug within the plugin itself.
Your best bet is to contact the plugin developer, tell them about the error, and ask whether it works with BP v1.1.1.