We notice that H2 DB works with OpenESB Standalone but in very few cases. The most important drawback are the user and password definitions when we use a Datasource to connect the database. We evaluate at the first glance (without further investigation) that the issue should come from the H2 Lib. When Users and Password are not defined, the connection works well !!!!
So we recommend against using H2 DB with OpenESB Standalone for the moment.
We Are waiting for further investigations