Help With The Rights Extension

Hi I am trying to use the rights extension in yii, but have to use sql server . I have been trying to recreate the schema in SQL Server 2012, but am reaching a stumbling block at this part

create table AuthItemChild

(

parent varchar(64) not null,

child varchar(64) not null,

primary key (parent,child),

foreign key (parent) references AuthItem (name) on delete cascade on update cascade,

foreign key (child) references AuthItem (name) on delete cascade on update cascade

);

This creates an error when saving of

Unable to create relationship ‘FK_AuthItemChild_AuthItem1’.

Introducing FOREIGN KEY constraint ‘FK_AuthItemChild_AuthItem1’ on table ‘AuthItemChild’ may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints. Could not create constraint. See previous errors.

Any ideas of a workaround , or whether it will work without the cascade ?

I also have another related issue where i cant have two datestamps in the user extensions user table, its giving me an error when saving a user

CDbCommand failed to execute the SQL statement: SQLSTATE[22007]: [Microsoft][SQL Server Native Client 11.0][SQL Server]Conversion failed when converting date and/or time from character string… The SQL statement executed was: INSERT INTO [dbo].[tbl_users] ([create_at], [lastvisit_at], [superuser], [status], [username], [password], [email], [activkey]) VALUES (:yp0, :yp1, :yp2, :yp3, :yp4, :yp5, :yp6, :yp7)