Please do not try to replace JBoss or Tomcat.
As far as the problem is concerned - we have Aware IM running on our dedicated server for months without problems. Sometimes problems may happen on computers with dynamically allocated IP addresses (from the hosting provider). When there is a change in the IP address Aware IM may stop working. Therefore we do not recommend running Aware IM in production when IP address of the machine can change dynamically.
We don't know if this is the same problem you are experiencing. If the problem happens again, please record the outputs of all servers - Tomcat, JBoss and Aware IM and send it to us.