> I'm sure I'm doing something wrong but I can't seem to get the
> correct version of the JayBird source to investigate. This is using
> the latest release (1.01 I think). Here's the stack trace:

This NPE happens when you call #clearWarnings() on the closed
connection (after the method FBManagedConnection#destroy() was called).

You can get latest sources of version 1.0.1 from CVS using branch
JayBird_1_0_1 revision:

cvs co -r JayBird_1_0_1 client-java

Roman