Description of problem:

When dashbuilder is started with default configuration (with H2 db) the dashbuilder.trace.db file gets filled with a huge amount of exceptions and the number of exception grows very fast when using the application (see attached trace file - 2.6MB of exceptions just after initial start of the application with no DB created).

The related problem is, that when the application is started, H2 database lock file (dashbuilder.lock.h2) stays present for much longer periods of time and after some application operations it even stays present permanently. I'm not entirely sure that this 2nd problem is related to the 1st, but it started to appear at the same time - after commits to dashbuilder project on github on May 17, 2013 (migration to Hibernate version 4.2)

Steps to Reproduce:
1. Build and run the latest version of dashbuilder with H2 database.
2. See the H2 db trace file ~/dashbuilder.trace.db. Also observer the long-lasting presence of dashbuilder.lock.db file after some operations.

Actual results:
-The dashbuilder.trace.db file is full of exceptions (about 2.6MB after clear startup)
org.h2.jdbc.JdbcSQLException: The object is already closed [90007-168]

-Also the lock file dashbuilder.lock.db is held for longer periods of time, and after some application operations the lock remains present permanently.

Expected results:
No exceptions in the H2 db trace file