This week's book giveaway is in the OCMJEA forum. We're giving away four copies of OCM Java EE 6 Enterprise Architect Exam Guide and have Paul Allen & Joseph Bambara on-line! See this thread for details.
Not sure about WebLogic Tomcat has will not timeout and cancel a long running script.
That error could be caused by someone closing their browser or moving to a different page before the servlet has finished sending the response. This is a somewhat normal occurrence in sites with slow pages.