problem (Guid)Membership.GetUser(User.Identity.Name).ProviderUserKey object not found

Hi, I'm looking for solution about my problem but I can't found and I do not have any idea. My problem: I have one the same application (in the same folder D:\MyApp) Binding more domain name (domain1, domain2, domain3,...) When I login in domain1 always is ok, but when I login in domain2, I got object not found: (Guid)Membership.GetUser(User.Identity.Name).ProviderUserKey In this case still shows (I was trying only for test): Button1.Text = Membership.ApplicationName; and shows applicationname Pls help