Hi,
I see your project you have the class view enabled, just open the solution explorer and the view should be fine.
Ok as far as I can tell, open solution explorer, click on content folder and then click on build, this will compile the content, then make sure than you use the name of the content object not the name.xnb.
Hope this help, I have the same problem sometimes so I need also to re-build the content separate from the solution.
hope this helps .. tuke me a while to figure out.