If I understand the two threads you refer to correctly, the problem is definitely with the way Windows handles sockets.
In addition to the solutions discussed in those two threads, you could have a look at http://www.jboss.org/modules/bb/index.html?module=bb&op=viewtopic&t=forums/ is a long shot, but probably worth trying.
Thanks for the link.
Unfortunately, no good. I changed the settings as suggested but I still get the problem.
A switch to Linux might be on the cards...