[ADMIN] problems after upgrading to 7.4.5

[Jags]

hi all experts
please help me 
here's the story...
i an working on a Java based Web Application
which is made up of
Jsp's -tomcat jsp server(3.1.1)
EJB's-Jonas EJBServer (2.4.4)
RDBMS-postgres (7.3.4)
JDK Platform is 1.4.2

the application was working fine with this config since 2 years 

then some while ago this app was upgraded to postgres v7.4.5 after which the 
problem started
Problem 1)     first when i started the jonas server i got an error saying
                   SET AUTOCOMMIT OFF is no longer supported.
Resolution 1): i downloaded pgjdbc2.jar and restarted the JOnas server
                   things looked to work  fine
Problem 2): when i tested the application it was running fine.i was able to add 
products to
                 the shopping cart and all the things
                 but when i restart the jonas server after some code changes
                 i started getting error in the cart such as
ERR#          EnqCartBean:viewEnqcart:fetchin 
enqMasterjava.rmi.ServerException: RemoteException occurred in server thread; 
nested exception is:
                  javax.transaction.TransactionRolledbackException: System 
exception in business method
                 the transaction got rolled back and all products in the cart 
were lost.
                 i tried by again adding the parts and the application started 
giving more and more errors
ERR#         CartDetailClient:Cannot create Cart detail: 
javax.transaction.NotSupportedException: Nested transactions not supported
ERR#          javax.transaction.TransactionRolledbackException: cannot register 
EntityContext
ERR#          EnqCartBean:addToEnqCartjavax.ejb.DuplicateKeyException: 
E0000053(even if 53 is not there)
Tries 1  : i tried by changing the newly available jdbc drivers from posgres.org
              1)pg74.216.jdbc2ee.jar
              2)pg74.216.jdbc3.jar and also others
            with these jars there was a strange issue i was able to connect and 
login to app but the product list
            and all the reporst were  not showing any records(this attempt also 
failed)
Tries 2 :  i learnt from the postgres site that SET AUTOCOMMIT OFF is not 
supported in 7.4
           so this might be a problem.so i set that option at postgres console by command 
SET "AUTOCOMMIT OFF"
           after this also problem is not solved
i am clue less about where actually the problem is it the driver i am using or 
there is a need to change the EJB code or
deployment descriptors.i'm new to EJB and also the code is quite old
pls help me.i have given it a real hard fight but no gains.basically where shud 
i attack
please mail me at
[EMAIL PROTECTED]
[EMAIL PROTECTED]
regards
jags

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