WordPress Issues Manager is a WordPress plugin made for those who want to have their own powerful system to deal with issues and tickets. This plugin uses WordPress custom post types and taxonomies and uses the WordPress latest APIs.
You can define as many projects as you want. And obviously, as many many issues per project as you want.
You can use this plugin for intern or public projects and decide to display or not your projects and their issues to your visitors. Your visitors can submit issues if they are logged in.
Get the plugin here: http://bit.ly/1pmajyr