> Jaybird RC4 has the same problem.

Please start your JBoss with -DFBLog4j=true, configure the logging in JBoss
(log4j.xml, category org.firebirdsql shold have the DEBUG priority) and post
the exception you get in that log.

The stacktrace you posted here does not contain any hint that the problem is
related to JayBird. The message "Interrupted while requesting permit" does
not come from the driver

Roman