Java EE (Java Enterprise Edition) General Discussion

Hi,
I've a JSP/servlet application;
All works fine,
but sometimes I receive this error:

INFO: Illegal access: this web application instance has been stopped already. Could not load java.net.BindException. The eventual following stack trace is caused by an error thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access, and has no functional impact.
java.lang.IllegalStateException
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1245)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1205)
at java.lang.ClassLoader.loadClassInternal(Unknown Source)
at com.mysql.jdbc.CommunicationsException.<init>(CommunicationsException.java:155)
at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:2652)
at com.mysql.jdbc.MysqlIO.quit(MysqlIO.java:1345)
at com.mysql.jdbc.Connection.realClose(Connection.java:4784)
at com.mysql.jdbc.Connection.cleanup(Connection.java:2040)
at com.mysql.jdbc.Connection.finalize(Connection.java:3296)
at java.lang.ref.Finalizer.invokeFinalizeMethod(Native Method)
at java.lang.ref.Finalizer.runFinalizer(Unknown Source)
at java.lang.ref.Finalizer.access$100(Unknown Source)
at java.lang.ref.Finalizer$FinalizerThread.run(Unknown Source)

But all continues to works fine;
This error seems do not involve any indesired effect.
So what is this?
What does it depends on?

Thank you in advance

MargNat