There is a bug on will_paginate gem on Rails 3.1 (see mislav/will_paginate#125) that compels me to use a different version (3.0.pre3) of that plugin.
I'm also using your nice admin_data to manage some of my tables, but until you declare a strict dependence to version 3.0.pre2 on your gem, I will not be able to run on Rails3...