TransactionRolledBack Exceptions using WebPhere under Unix

[Jeroen]

I am working on WAS 3.6 and VisualAge. I have developed CMP entity
beans and session beans which use the CMP beans.
All my read methods work fine, but when I want to create a new row or
update an existing one in a Oracle database I use I get a
TransactionRolledBack Exception on the post-invoke.
The strange thing is that this only happens on a Unix environment. (I
have a test server on Windows NT that works fine). I can't find any
differences in configuration between the two platforms and the
database driver is also the same. (Oracle thin driver).

The Exception:

javax.transaction.TransactionRolledbackException: CORBA
TRANSACTION_ROLLEDBACK 0 No; nested exception is:
org.omg.CORBA.TRANSACTION_ROLLEDBACK:
com.ibm.websphere.csi.CSITransactionRolledbackException:
at com.ibm.ejs.csi.TranStrategy.commit(TranStrategy.java:185)
at com.ibm.ejs.csi.TranStrategy.postInvoke(TranStrategy.java:59)
at com.ibm.ejs.csi.TransactionControlImpl.postInvoke(TransactionControlImpl.java:407)
at com.ibm.ejs.container.EJSContainer.postInvoke(EJSContainer.java:1754)
com.ibm.CORBA.iiop.ExtendedServerDelegate.dispatch(ExtendedServerDelegate.java:506)
at com.ibm.CORBA.iiop.ORB.process(ORB.java:2261)
at com.ibm.CORBA.iiop.WorkerThread.run(WorkerThread.java(Compiled
Code))
at com.ibm.ejs.oa.pool.ThreadPool$PooledThread.run(ThreadPool.java:535)
minor code: 0 completed: No

The WebSphere log:
[02.11.13 10:23:45:164 CET]cef1cded OnePhaseConne W Illegal use of 1
phase resource in transaction, 2 phase commit was attempted with 1
phase resource.

Can somebody tell me what is causing this problem (and why there is a
difference in platforms)??