New Project, downloaded umbraco 7 via Nuget.  I'm having to clear my chrome history almost constantly when debugging in order to keep from getting the error below.  Any ideas how to fix this problem?

[NullReferenceException: Object reference not set to an instance of an object.]
   umbraco.BusinessLogic.User..ctor(IUser user) +113
   Umbraco.Web.UmbracoContext.get_UmbracoUser() +84
   Umbraco.Web.UmbracoContext.DetectInPreviewModeFromRequest() +246
   Umbraco.Web.UmbracoContext.get_InPreviewMode() +85
   Umbraco.Web.PublishedCache.ContextualPublishedCache.HasContent() +47
   Umbraco.Web.UmbracoModule.EnsureHasContent(UmbracoContext context, HttpContextBase httpContext) +68
   Umbraco.Web.UmbracoModule.EnsureUmbracoRoutablePage(UmbracoContext context, HttpContextBase httpContext) +182
   Umbraco.Web.UmbracoModule.ProcessRequest(HttpContextBase httpContext) +509
   Umbraco.Web.UmbracoModule.<Init>b__a(Object sender, EventArgs e) +132
   System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +136
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +69