After updating Entity Framework model, Visual Studio does not see changes
First Build your Project and if it was successful, right click on the "model.tt" file and choose run custom tool. It will fix it.
Again Build your project and point to "model.context.tt" run custom tool. it will update DbSet lists.
If this is the bug with the edmx file located in a folder it is now fixed - download and install VS 2012 Update 1. You can get it from: http://www.microsoft.com/visualstudio/eng/downloads#d-visual-studio-2012-update