PostgreSQL exceptions unusable

I run xwiki on postgresql and see a lot of exceptions when storing documents. An example is posted below. A big problem in that stacktrace is that the ACTUAL error is not present in it! The actual error that occured can only be seen when getNextException is called on the original exception, and this is not part of the exception logging code. Because this info is not present it is hard to know what goes wrong...
I know that this method of creating exceptions is idiotic but sadly enough it IS used by PostgreSQL.

---- Stack dump ----
Error number 3201 in 3: Exception while saving document
Main.AanmakenUpdate
Wrapped Exception: Could not execute JDBC batch update
com.xpn.xwiki.XWikiException: Error number 3201 in 3: Exception while saving
document Main.AanmakenUpdate
Wrapped Exception: Could not execute JDBC batch update
        at
com.xpn.xwiki.store.XWikiHibernateStore.saveXWikiDoc(XWikiHibernateStore.jav
a:538)
        at
com.xpn.xwiki.store.XWikiCacheStore.saveXWikiDoc(XWikiCacheStore.java:97)
        at
com.xpn.xwiki.store.XWikiCacheStore.saveXWikiDoc(XWikiCacheStore.java:91)
        at com.xpn.xwiki.XWiki.saveDocument(XWiki.java:1111)
        at com.xpn.xwiki.web.SaveAction.save(SaveAction.java:120)
        at com.xpn.xwiki.web.SaveAction.action(SaveAction.java:129)
        at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:201)
        at
org.apache.struts.action.RequestProcessor.processActionPerform(RequestProces
sor.java:431)
        at
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
        at
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
        at
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
        at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
FilterChain.java:252)
        at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
ain.java:173)
        at
com.xpn.xwiki.web.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFi
lter.java:117)
        at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
FilterChain.java:202)
        at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
ain.java:173)
        at
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.ja
va:213)
        at
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.ja
va:178)
        at
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126
)
        at
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105
)
        at
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java
:107)
        at
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
        at
org.apache.jk.server.JkCoyoteHandler.invoke(JkCoyoteHandler.java:199)
        at
org.apache.jk.common.HandlerRequest.invoke(HandlerRequest.java:282)
        at org.apache.jk.common.ChannelSocket.invoke(ChannelSocket.java:754)
        at
org.apache.jk.common.ChannelSocket.processConnection(ChannelSocket.java:684)
        at
org.apache.jk.common.ChannelSocket$SocketConnection.runIt(ChannelSocket.java
:876)
        at
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.jav
a:684)
        at java.lang.Thread.run(Thread.java:595)
 
 
Wrapped Exception:
 
java.sql.BatchUpdateException: Batch entry 0 insert into xwikircs (XWR_DATE,
XWR_COMMENT, XWR_AUTHOR, XWR_DOCID, XWR_VERSION1, XWR_VERSION2) values
(2008-10-13 09:38:49.000000 +02:00:00, , XWiki.lenzo, -1030818576, 4, 1) was
aborted.  Call getNextException to see the cause.
        at
org.postgresql.jdbc2.AbstractJdbc2Statement$BatchResultHandler.handleError(A
bstractJdbc2Statement.java:2530)
        at
org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.ja
va:1317)
        at
org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:350)
        at
org.postgresql.jdbc2.AbstractJdbc2Statement.executeBatch(AbstractJdbc2Statem
ent.java:2592)
        at
org.apache.commons.dbcp.DelegatingStatement.executeBatch(DelegatingStatement
.java:294)
        at
org.apache.commons.dbcp.DelegatingStatement.executeBatch(DelegatingStatement
.java:294)
        at
org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:48)
        at
org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:246)
        at
org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:237)
        at
org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:141)
        at
org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(Abst
ractFlushingEventListener.java:298)
        at
org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventL
istener.java:27)
        at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1000)
        at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:338)
        at
org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:106)
        at
com.xpn.xwiki.store.XWikiHibernateBaseStore.endTransaction(XWikiHibernateBas
eStore.java:781)
        at
com.xpn.xwiki.store.XWikiHibernateBaseStore.endTransaction(XWikiHibernateBas
eStore.java:752)
        at
com.xpn.xwiki.store.XWikiHibernateStore.saveXWikiDoc(XWikiHibernateStore.jav
a:528)
        at
com.xpn.xwiki.store.XWikiCacheStore.saveXWikiDoc(XWikiCacheStore.java:97)
        at
com.xpn.xwiki.store.XWikiCacheStore.saveXWikiDoc(XWikiCacheStore.java:91)
        at com.xpn.xwiki.XWiki.saveDocument(XWiki.java:1111)
        at com.xpn.xwiki.web.SaveAction.save(SaveAction.java:120)
        at com.xpn.xwiki.web.SaveAction.action(SaveAction.java:129)
        at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:201)
        at
org.apache.struts.action.RequestProcessor.processActionPerform(RequestProces
sor.java:431)
        at
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
        at
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
        at
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
        at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
FilterChain.java:252)
        at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
ain.java:173)
        at
com.xpn.xwiki.web.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFi
lter.java:117)
        at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
FilterChain.java:202)
        at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
ain.java:173)
        at
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.ja
va:213)
        at
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.ja
va:178)
        at
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126
)
        at
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105
)
        at
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java
:107)
        at
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
        at
org.apache.jk.server.JkCoyoteHandler.invoke(JkCoyoteHandler.java:199)
        at
org.apache.jk.common.HandlerRequest.invoke(HandlerRequest.java:282)
        at org.apache.jk.common.ChannelSocket.invoke(ChannelSocket.java:754)
        at
org.apache.jk.common.ChannelSocket.processConnection(ChannelSocket.java:684)
        at
org.apache.jk.common.ChannelSocket$SocketConnection.runIt(ChannelSocket.java
:876)
        at
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.jav
a:684)
        at java.lang.Thread.run(Thread.java:595)