FYI, I have upgraded my Linux machines to SuSE 9.2 (SuSE kernel 2.6.8-24.3). On one of them, with JDK 1.4, during an m:rebuild-all, I got a JDK crash in an NIO accept() in the unit tests in our remoting stuff. I got that a few times in a row, then a while later got a test failure instead (with an address in use during bind) also in the remoting tests. I tried JDK 1.4.2_05 and _06 and both had the problem. On another machine with the same distro/kernel, JMXRemotingTest hangs (both sides of the asyc conversation seem to be blocked on read).
In any of these cases JDK 1.5 seems fine, so I'm guess there is some sort of kernel compatibility problem with 1.4 NIO networking going on. Aaron