Cannot commit when autoCommit is enabled error

Dear group,
We have been using postgresql-jdbc-8.3-604, and recently we started using
postgresql-jdbc-9.2, everything seems working fine, except we are getting
this error and could not find the solution yet. This related to our
reporting and I could say that it is not happening every report we run. If
you could help, I really appreciated.
Below is the part of the code and error that we are getting. Thanks.

ERROR:
ERROR in createReportTable(): Cannot commit when autoCommit is enabled.
org.postgresql.util.PSQLException: Cannot commit when autoCommit is enabled.
at
org.postgresql.jdbc2.AbstractJdbc2Connection.commit(AbstractJdbc2Connection.java:703)
at sun.reflect.GeneratedMethodAccessor65.invoke(Unknown Source)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at
org.apache.tomcat.jdbc.pool.ProxyConnection.invoke(ProxyConnection.java:126)
at
org.apache.tomcat.jdbc.pool.JdbcInterceptor.invoke(JdbcInterceptor.java:109)
at
org.apache.tomcat.jdbc.pool.DisposableConnectionFacade.invoke(DisposableConnectionFacade.java:80)
at $Proxy0.commit(Unknown Source)
at sun.reflect.GeneratedMethodAccessor65.invoke(Unknown Source)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at
org.hibernate.jdbc.BorrowedConnectionProxy.invoke(BorrowedConnectionProxy.java:40)
at $Proxy125.commit(Unknown Source)
at
com.resolution.scheduler.dao.hibernate.SalesPAFNewDaoHibernate.runStorageSQLQuery(SalesPAFNewDaoHibernate.java:219)
at
com.resolution.scheduler.service.impl.SalesPAFNewManagerImpl.runStorageSQLQuery(SalesPAFNewManagerImpl.java:151)

PART OF THE CODE:

public Integer runStorageSQLQuery(String sqlQuery) throws Exception {
int results=0;
try {
java.sql.Connection conn = getSession().connection();
boolean acs = conn.getAutoCommit();
//System.out.println("...................AutoCommit status:
"+acs);
conn.setAutoCommit(false);
java.sql.PreparedStatement st = conn.prepareStatement(sqlQuery);
results = st.executeUpdate();
conn.commit();
conn.setAutoCommit(acs);
st.close();
} catch (Exception e) {
System.err.println("ERROR in runStorageSQLQuery(): " +
e.getMessage() + " sqlQuery: "+sqlQuery);
e.printStackTrace();
}
return new Integer(results);
}