Our blog was recently updated to WP3.3 and the Most Popular plugin stopped working. We have this deployed in both the sidebar (via widget) as well as after post content (also via widget). Curiously, we are having no problems with the nRelate Related Content plugin via widget.
The plugin is giving no errors otherwise, and the widget still shows up in the widget section as it always has. Also, inspecting where the content should appear on the page and code is still showing up there. Only nothing is displaying on the page.