[jboss-user] newbie qustion: zombie jboss processes

Hello, I'm running a jboss app-server to host a soap service and a flex app that server data from a mysql-db. The system runs on debian-linux. The hardware is probably too slow to handle the load effectively sometimes. After some time a lot of jboss processes, appear in the process tree. These are sleeping and seem to be hanging. Could the performance limit of the machine be the cause? Furthermore are there settings that can help to solve the problem? Sorry, if these are obvious questions, but I'm new to jboss. I would also appreciate a pointer to an faq or other sources of information. Thank you Jacques