ORA-17401 Protocol violation

I have started another project which is similar to a previous ERP....

I just chzanged the persistance and oracle ds settings and created a new db schema

now each time I run the app now it gives the following error

ORA-17401

Protocol violation

java.sql.SQLException: Refcursor value is invalid

...Th queries is running fine on sql+ but while running web app, it crashes..

Well dont know if this is jugari but:

in persistance.xml

I just increased the batch size, but is it right to limit it?

Cant I make it unlimited?