The same happened to me in Sun app server 9.0 in Ubuntu. I can reproduce the problem. However, when I used fedora 6 , or solaris 10 with glassfish V2 and with OS tunning in the documention, that hanging never occured, but more than 60% requests were timed-out. (SSL timout).
[Message sent by forum member 'hendahewa' (hendahewa)]
http://forums.java.net/jive/thread.jspa?messageID=233185