"Broken Pipe" in JDBC due session autorefresh (no replies)

Hi!
I have a Tomcat application with two database connecctions: JDBC and Hibernate ones. The Hibernate connection fails after 20 hours of inactivity due c3po session auto-refresh (free memory: 213412744 at that moment). Here is a stack trace:

at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:2652)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1554)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1665)
at com.mysql.jdbc.Connection.execSQL(Connection.java:3176)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1153)
at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1266)
at com.mchange.v2.c3p0.impl.NewProxyPreparedStatement.executeQuery(NewProxyPreparedStatement.java:116)
at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.extract(ResultSetReturnImpl.java:80)
... 44 more


Could you help me with that? Hibernate forim said that it is clearly MySQL case. I have tryed to use DataSource and several sets of c3po properties with no effect. Help me please?