BUG #2877: Caused by: org.postgresql.util.PSQLException: Unknown Response Type

The following bug has been logged online:

Bug reference: 2877
Logged by: Ravalison Frederyk
Email address: fravali(at)yahoo(dot)fr
PostgreSQL version: 8.1
Operating system: win 2003
Description: Caused by: org.postgresql.util.PSQLException: Unknown
Response Type
Details:

Sometimes in my J2EE web application, I have the following problems:
Caused by: org.postgresql.util.PSQLException: Unknown Response Type
at org.postgresql.core.QueryExecutor.executeV3(QueryExecutor.java:192)
at org.postgresql.core.QueryExecutor.execute(QueryExecutor.java:100)
at org.postgresql.core.QueryExecutor.execute(QueryExecutor.java:43)
at
org.postgresql.jdbc1.AbstractJdbc1Statement.execute(AbstractJdbc1Statement.j
ava:517)
at
org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.j
ava:50)
at
org.postgresql.jdbc1.AbstractJdbc1Statement.executeQuery(AbstractJdbc1Statem
ent.java:233)
at
org.hibernate.jdbc.AbstractBatcher.getResultSet(AbstractBatcher.java:139)
at org.hibernate.loader.Loader.getResultSet(Loader.java:1669)
at org.hibernate.loader.Loader.doQuery(Loader.java:662)
at
org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.ja
va:224)
at org.hibernate.loader.Loader.loadCollection(Loader.java:1919)
... 50 more

The Unknown Response Type will change each page load. To resolve the
probleme, I have to restart Jonas.

My configuration:
Jonas 4.5.3
pg74.216.jdbc3
Postgres 8.1

Thanks