JBPM or hibernate issue?

[tejjbpm]

Hi, I have implemented jbpm 4.2 on Tomcat 6.0.20. But recently i have found that tomcat hangs if was not restarted for few days. Also all my pages where JBPM is used i get this "could not acquire block of ids" error. I think the whole issue is something to do with hibernate and cleanup .This is how my hibernate looks - did i miss any setting.  I also tried to use reconnect=true in my database connection setting and this is causing more issue and the whole database connections seems to be reconnected after every few minutes and creates a instable system. I am confused as to how to solve this one - please can anybody help me out. The reconnection errors are going off only if the tomcat is restarted

<hibernate-configuration>

          <session-factory>

          <property name="hibernate.dialect">org.hibernate.dialect.MySQLInnoDBDialect</property>

          <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>

    <property name="hibernate.connection.url">jdbc:mysql://localhost/project</property>

    <property name="hibernate.connection.username">mysqlroot</property>

    <property name="hibernate.connection.password">password</property>

            <!--

          <property name="connection.datasource">java:comp/env/jdbc/project</property>

          <property name="transaction.factory_class">org.hibernate.transaction.JTATransactionFactory</property>

          <property name="jta.UserTransaction">java:comp/UserTransaction</property> -->

    <property name="hibernate.format_sql">true</property>

    <property name="hibernate.cache.provider_class">org.hibernate.cache.HashtableCacheProvider</property>

                    <mapping resource="jbpm.repository.hbm.xml" />

                    <mapping resource="jbpm.execution.hbm.xml" />

                    <mapping resource="jbpm.history.hbm.xml" />

                    <mapping resource="jbpm.task.hbm.xml" />

                    <mapping resource="jbpm.identity.hbm.xml" />

          </session-factory>

</hibernate-configuration>