no network connection with java apps on debian lenny

If you are experiencing problem like no network connection on debian (the current testing distribution - squeeze for me) from java applications. Ex:

"java.net.SocketException: Network is unreachable"

but, connection is working for others kinds of apps probably you can solve it: editing file
/etc/sysctl.d/bindv6only.conf
and set net.ipv6.bindv6only 0
and after /etc/init.d/invoke-rc.d procps restart (to reboot procfs).

Seems that the jdk is not managing correctly ipv6 connections...
The bug is reported for sun-jdk and open-jdk packages.

source.