problem in connection pool

hi all

i have created a datasource in weblogic6.0 connected in to database in EJB.

But the problem is on weblogic server consol it is thorowing exceptions in equal intervels of time.

is it a problem with any one of the attribute values like

refresh period,

shrink period.

i am giving the exception messages below

thanks

Narendra

java.sql.SQLException: ORA-29532: Java call terminated by uncaught Java exceptio

n: java.lang.NullPointerException

ORA-06512: at "SYS.JAVA_XA", line 0

ORA-06512: at line 1

at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:114)

at oracle.jdbc.ttc7.TTIoer.processError(TTIoer.java:208)

at oracle.jdbc.ttc7.Oall7.receive(Oall7.java:542)

at oracle.jdbc.ttc7.TTC7Protocol.doOall7(TTC7Protocol.java:1311)

at oracle.jdbc.ttc7.TTC7Protocol.parseExecuteFetch(TTC7Protocol.java:738

)

at oracle.jdbc.driver.OracleStatement.executeNonQuery(OracleStatement.ja

va:1313)

at oracle.jdbc.driver.OracleStatement.doExecuteOther(OracleStatement.jav

a:1232)

at oracle.jdbc.driver.OracleStatement.doExecuteWithBatch(OracleStatement

.java:1353)

at oracle.jdbc.driver.OracleStatement.doExecute(OracleStatement.java:176

at oracle.jdbc.driver.OracleStatement.doExecuteWithTimeout(OracleStateme

nt.java:1805)

at oracle.jdbc.driver.OraclePreparedStatement.executeUpdate(OraclePrepar

edStatement.java:322)

at oracle.jdbc.driver.OraclePreparedStatement.execute(OraclePreparedStat

ement.java:366)

at oracle.jdbc.xa.client.OracleXAResource.start(OracleXAResource.java:10

at weblogic.transaction.internal.ServerResourceInfo.start(ServerResource

Info.java:994)

at weblogic.transaction.internal.ServerResourceInfo.xaStart(ServerResour

ceInfo.java:947)

at weblogic.transaction.internal.ServerResourceInfo.enlist(ServerResourc

eInfo.java:206)

at weblogic.transaction.internal.ServerTransactionImpl.enlistResource(Se

rverTransactionImpl.java:316)

at weblogic.jdbc.common.internal.ConnectionEnv.test(ConnectionEnv.java:6

61)

at weblogic.common.internal.ResourceAllocator.trigger(ResourceAllocator.

java:1010)

at weblogic.time.common.internal.ScheduledTrigger.executeLocally(Schedul

edTrigger.java:225)

at weblogic.time.common.internal.ScheduledTrigger.execute(ScheduledTrigg

er.java:216)

at weblogic.time.server.ScheduledTrigger.execute(ScheduledTrigger.java:6

at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:137)

at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:120)