Problem Of Duplicate Records With A Simple Insert Statement !

 

I am using a simple stored proc shown below which inserts a record and updates the same record field
called SortID with the Primary Key Column data of the same record.
Everything was working fine until few days back. The site has been deployed 2 years back and was LIVE ever since.

We have got thousands of records in this Credits table. The table field called SortID is used
for moving the credits up and down.

My problem is now after 2 years of deploying the table has got duplicate records, suprisingly a same credit is appearing
under different MemberID and with the same SortID.

How are these duplicate records inserted with a simple insert statement & update ??

Is this a Locking problem or Transaction problem I have no idea.

Any ideas will be of great help

Thanks in Advance

Stored Procedure Used


CREATE PROC SP_SC_INSERT
(
@memberID int,
@title varchar(30),
@dir varchar(30),
@desc varchar(20)
)
AS

INSERT INTO [dbo].[Credits]
(
[MemberID],
[Title],
[Director],
[Description],
)
VALUES
(
@memberID,
@title,
@dir,
@desc,

)
UPDATE Credits Set SortID = @@IDENTITY WHERE CreditID = @@IDENTITY
GO