I have the same problem, and i have a  solution maybe this could help you.  You can alter the existing stored procedure[DeleteUser].

 

ALTER procedure [dbo].[DeleteUser]
 
@UserId   int
 
as
declare @username as nvarchar(50)
declare @unique_userid as uniqueidentifier

delete from dbo.userroles where userid=@UserId
delete from dbo.ModulePermission  where userid=@UserId
delete from dbo.TabPermission where userid=@UserId


--remove orphan user
select @username=username from Users  where UserId = @UserId
select @unique_userid=userid from  dbo.aspnet_Users where userName=@username
delete from  dbo.aspnet_Membership  where userid=@unique_userid
delete from  dbo.aspnet_Users  where userid=@unique_userid


delete  from dbo.Users  where  UserId = @UserId