An I/O error occured while sending to the backend

Hello,

I have a problem that I am not able to solve. I have this exception:

org.postgresql.util.PSQLException: An I/O error occured while sending to
the backend.
at
org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:216)
at
org.postgresql.jdbc2.AbstractJdbc2Connection.executeTransactionCommand(AbstractJdbc2Connection.java:649)
at
org.postgresql.jdbc2.AbstractJdbc2Connection.rollback(AbstractJdbc2Connection.java:686)
at com.evermind._id.rollback(.:196)
at com.evermind._ja.rollback(.:104)
at com.evermind._bs._gbc(.:118)
at com.evermind.server.ApplicationServerTransaction._gcc(.:334)
at com.evermind.server.ApplicationServerTransaction._gbc(.:296)
at com.evermind.server.ApplicationServerTransaction.rollback(.:279)
at
com.evermind.server.ApplicationServerTransactionManager.rollback(.:285)
at
cz.iiprg.util.importer.ejb.ImporterEJB.rollbackTransaction(ImporterEJB.java:173)
at
Importer_StatefulSessionBeanWrapper34.rollbackTransaction(Importer_StatefulSessionBeanWrapper34.java:416)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at com.evermind._bt._uab(.:79)
at com.evermind._bf.run(.:62)
Caused by: java.io.IOException: Stream closed
at sun.nio.cs.StreamEncoder.ensureOpen(StreamEncoder.java:38)
at sun.nio.cs.StreamEncoder.flush(StreamEncoder.java:151)
at java.io.OutputStreamWriter.flush(OutputStreamWriter.java:213)
at org.postgresql.core.PGStream.flush(PGStream.java:501)
at
org.postgresql.core.v3.QueryExecutorImpl.sendSync(QueryExecutorImpl.java:674)
at
org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:189)
... 17 more

It is strange that it occurs randomly and only when the server is loaded.

Radek