Sun Java 1.4.x can't open network sockets on recent rawhides

[Robin Green <greenrd presidium org>]

The Sun JVM for Linux, version 1.4.2_08-b03, has difficulties opening
(any?) outbound network sockets with recent rawhide kernel/libc. Version
1.5.0, and GNU Interpeter for Java, don't exhibit this problem - it's only
the Sun 1.4.x series.

Not sure if this is a sun bug, or a glibc bug or kernel
bug... so I'm not sure whose bug database to file it in, if any.

Suggestions?
-- 
Robin