Fixed CalendarMembershipProvideTest tests. They didn't work with Fake repository, because in CalendarMembershipProvider class methods were calls new RepoUnit(). Exctually, I've left everything as it was, just changed Fake repository to real database.
Fixed tests in CalendarRoleProviderTest. There were errors in Linq Expressions. While using FakeRepository everything seemed to be okay, using Object::ToString() method in Expressions together with Entity Framework caused exceptions. Fixed them, fixed the same problems in CalendarRoleProvider class.
Some places with unknown behavior I marked by throwing NotImplementedException().