'Guests' role could not be loaded

I've downloaded the source for V2.5 but when I build my project I get the following error:

{"'Guests' role could not be loaded"}

Nop.Core.NopException was unhandled by user code
  Message='Guests' role could not be loaded
  Source=Nop.Services
  StackTrace:
       at Nop.Services.Customers.CustomerService.InsertGuestCustomer() in C:\Visual Studio 2010\Projects\nopCommerce 2.5\Libraries\Nop.Services\Customers\CustomerService.cs:line 385
       at Nop.Web.Framework.WebWorkContext.GetCurrentCustomer() in C:\Visual Studio 2010\Projects\nopCommerce 2.5\Presentation\Nop.Web.Framework\WebWorkContext.cs:line 117
       at Nop.Web.Framework.WebWorkContext.get_CurrentCustomer() in C:\Visual Studio 2010\Projects\nopCommerce 2.5\Presentation\Nop.Web.Framework\WebWorkContext.cs:line 185
       at Nop.Web.MvcApplication.SetWorkingCulture() in C:\Visual Studio 2010\Projects\nopCommerce 2.5\Presentation\Nop.Web\Global.asax.cs:line 201
       at Nop.Web.MvcApplication.Application_AuthenticateRequest(Object sender, EventArgs e) in C:\Visual Studio 2010\Projects\nopCommerce 2.5\Presentation\Nop.Web\Global.asax.cs:line 146
       at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
       at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)
  InnerException: 

Anyone with any insight on this?  I've downloaded a clean version of V2.5 and tried to run it w/o any modifications yet I still get this error when the site tries to load up.

Bump, is there something I'm missing with the new source?  I didn't have this issue with 2.4.