If you have the time to invest this is how we should continue.
0. check sourceforge for similar reports..
1. test on the latest jboss-3.0.x (6).
2. compare Jetty and Tomcat integrations...
This will tell us whether the problem has already been fixed and whether it is in the webcontainer (integration) or Jboss itself.
If you get back to me with the results of these tests, we can decide how to go forward..