TFS 2010 SharePoint Project Portal 403 Forbidden

When you try to open or create the workitem through the project portal you'll get an 403 forbidden error. This is because you have not enough privileges to the folder Inetpub\wwwroot\bin at the TFS server machine.

Just set the next rights to the all domain users.

From IT Blog Posts

Via http://www.cnblogs.com/patrick/archive/2010/04/30/1725167.html