We have such code:

[Serializable]
    [HierarchyRoot(InheritanceSchema = InheritanceSchema.SingleTable)]
    public abstract class Employee : Entity
    {
        [Field, Key]
        public int Id { get; set; }

    [Field]
    public string Name { get; set; }

    [Field]
    public EmployeeAccount Account { get; set; }

    [Field]
    public string Login { get; set; }

    [Field]
    public string Pass { get; set; }

    [Field]
    public int Code { get; set; }

}

public class OfflineManager : Employee
    {
        [Field]
        public Store Store { get; set; }
}

public class StoreManager : Employee
    {
        [Field]
        public Store Store { get; set; }
    }
public class ShopManager : Employee
    {
        [Field]
        public Store Store { get; set; }
    }
[Serializable]
    [HierarchyRoot]
    public class Store : Entity
    {
        [Field, Key]
        public int Id { get; set; }
    [Field]
    public string Name { get; set; }        
}

And usage:

var store = new Store();
var manager = new ShopManager();
manager.Store = store;

And we get error "constraint violation".

I think, we found the cause of this behavior.

DO makes correct table structure, but incorrect foreign keys.

Here is table:

CREATE TABLE [dbo].Employee ON [PRIMARY]

And FKs:

ALTER TABLE [dbo].[Employee]  WITH CHECK ADD  CONSTRAINT [FK_OfflineManager-Store-Store_Store] FOREIGN KEY([Store.Id])
REFERENCES [dbo].[Store] ([Id])
GO

ALTER TABLE [dbo].[Employee]  WITH CHECK ADD  CONSTRAINT [FK_ShopManager-Store-Store_Store] FOREIGN KEY([Store.Id])
REFERENCES [dbo].[Store] ([Id])
GO
ALTER TABLE [dbo].[Employee]  WITH CHECK ADD  CONSTRAINT [FK_StoreManager-Store-Store_Store] FOREIGN KEY([Store.Id])
REFERENCES [dbo].[Store] ([Id])
GO

We have [FK_OfflineManager-Store-Store_Store] on [Store.Id] field. There is no prefix on this field, but perhaps it should be so on first field.

We have next fields with prefix: [StoreManager.Store.Id], [ShopManager.Store.Id].

But in FK we see only [Store.Id], and no [StoreManager.Store.Id] or [ShopManager.Store.Id].

So we consider, that fields generating is ok and generating of foreign keys have the bag. Although I think that DO should add prefixes with class name to all fields when inheritance is SingleTable.

We were a bit confused by the lack of [OfflineManage.Store.Id] field :)