Entity Bean Locking and Deadlock Detection

I developed a system using java 5 and jboss 4.0.4 with j2ee technology. when 2 users try to do same transaction, i recievedfollowing SQL exception

com.microsoft.sqlserver.jdbc.SQLServerException: The COMMIT TRANSACTION request has no corresponding BEGIN TRANSACTION.

and finnaly a dead lock is recieved.

i have searched this in internet and i found a document how to avoid dead locks. so i inserted following tags to jboss.xml accoring to the doc.

<entity>

<ejb-name>MyBMPBean</ejb-name>

<jndi-name>MyBMP</jndi-name>

<configuration-name>

Instance Per Transaction BMP EntityBean

</configuration-name>

</entity>

but still i'm recieving this sql exception.

pls help me to solve this.

[813 byte] By [kaviratnea] at [2007-11-26 14:32:26]