> Copied a tomcat webapp from one machine to another.

I would suspect that connection is closed automatically because of some
"fatal" error. Can it be that you have changed the server or the database?
What happens if you enable log4j? In this case most likely there is one more
exception before that one.

Also, what you can do, is to change the driver a bit and dump stack trace in
FBConnection.close(). You will know where it was closed, maybe there is
something in Tomcat...

And finally, what prevents you from switching to JayBird 1.5.5 or even
JayBird 2.0.0 beta 2 at least for testing purposes?

Roman