Stale Database Connections in Production Environment - Oracle 9.0.4.1

Question

Every so often we encounter stale database connections in our connection pools. To us, this should not happen, as the connections should be refreshed, if idle, every so often.
Please see the data-sources entry below for an example connection pool. They are all pretty much the same. We have a retry-interval and inactivity-timeout specified!
Are we missing something obvious.. Any help at all on this would be much appreciated as this is an ongoing issue in a real-time CRM type application currently running in Production.
Cheers in advance.
data-source class="oracle.jdbc.pool.OracleConnectionCacheImpl" location="jdbc/COMMONCoreDS" password="" min-connections="10" username="" url="" xa-location="jdbc/xa/COMMONXADS" inactivity-timeout="60" connection-driver="oracle.jdbc.driver.OracleDriver" wait-timeout="10" max-connect-attempts="3" max-connections="45" name="COMMONDS" ejb-location="jdbc/COMMONDS" connection-retry-interval="30" stmt-cache-size="200">
          <description>Oracle DataSource to Common Schema</description>
     </data-source>

Answer 1

public Connection borrowConnection() throws SQLException
logger.debug("borrowConnection");
Connection conn = null;
try
conn = mDatasource.getConnection();
conn.setAutoCommit(false);
if (conn==null)
logger.fatal("Borrow connection failed");
throw new SQLException();
catch(SQLException e)
logger.fatal("Borrow connection failed",e);
throw e;
return conn;
public static void releaseConnection(Connection conn)
logger.debug("releaseConnection");
try
if (conn!=null)
conn.close();
catch(SQLException e)
logger.warn(e);