Facebook.Web.Contracts - strong signature could not be verified?

I've been going through the tutorial for the .NET Facebook SDK on codeplex. I used Nuget to install the SDK, as the tutorial indicates. However, when I try to run the application, I get the following exception:

Could not load file or assembly 'Facebook.Web.Contracts' or one of its dependencies. Strong name signature could not be verified. The assembly may have been tampered with, or it was delay signed but not fully signed with the correct private key. (Exception from HRESULT: 0x80131045)

This is with version FacebookWeb 5.0.8.0. Any ideas?

This problem appears to be fixed in 5.0.9