java.net.SocketException: Broken pipe

I'm running an engine with 15 databases, with fair amount of load.

Every 4-5 days I'm getting error like this from the java side and the
application stops working (and wont come back unless I restart the
webapplication):

java.net.SocketException: Broken pipe
at java.net.SocketOutputStream.socketWrite0(Native Method)
at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:92)
at java.net.SocketOutputStream.write(SocketOutputStream.java:136)
at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:66)
at java.io.BufferedOutputStream.write(BufferedOutputStream.java:110)
at java.io.FilterOutputStream.write(FilterOutputStream.java:80)
at org.postgresql.PG_Stream.Send(PG_Stream.java:87)
at org.postgresql.core.QueryExecutor.sendQuery(QueryExecutor.java:184)
at org.postgresql.core.QueryExecutor.execute(QueryExecutor.java:71)
at
org.postgresql.jdbc1.AbstractJdbc1Connection.ExecSQL(AbstractJdbc1Connection.java:505)
at
org.postgresql.jdbc1.AbstractJdbc1Statement.execute(AbstractJdbc1Statement.java:360)
at
org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:48)
at
org.postgresql.jdbc1.AbstractJdbc1Statement.executeQuery(AbstractJdbc1Statement.java:176)
at
org.postgresql.jdbc1.AbstractJdbc1Statement.executeQuery(AbstractJdbc1Statement.java:163)
at
org.apache.commons.dbcp.DelegatingStatement.executeQuery(DelegatingStatement.java:162)
at
com.eplica.model.persistence.JDBCPersistenceHelper.findByUniqueSql(JDBCPersistenceHelper.java:704)

Does anyone know what this is about ?
I'm using Red hat Enterprise, and all the correct JDBC drivers etc,
using Jakarta DHCP connection pooling, and standard sql sentences.

thanx
-reynir