Message when running web application in Tomcat from NetBeans?

Question

Hello

Is anyone able to shed any light on the message 'SEVERE: A web application appears to have started a thread named [DefaultQuartzScheduler_Worker-5] but has failed to stop it. This is very likely to create a memory leak.'?

The message is generated a number of times when a web application is launched from NetBeand 6.9.1 using Tomcat 6.0.26?

The project, a collection of Java servlets and JSPs, does include two Quartz jobs submitted when the server starts.

Thanks

Mr Morgan.