#49 Error during the creation of the DataBase Example

[Juan Nova]

I'm using de Derby Database, Apache 5.5 and j2sdk1.4.2_19 but i have a problem. After do the deploy i run the tomcat a the following error appear:
2009-01-19 16:56:36,281 INFO org.freebxml.omar.server.persistence.rdb.ConnectionPool[org.freebxml.omar.server.cache.ServerCache#initialize] - Database connection pooling enabled
2009-01-19 16:56:36,296 INFO org.freebxml.omar.server.persistence.rdb.ConnectionPool[org.freebxml.omar.server.cache.ServerCache#initialize] - Total connections: 20 Available: 20 Checked-out: 0 []
2009-01-19 16:56:37,312 INFO org.freebxml.omar.server.repository.hibernate.RepositoryHibernateUtil[org.freebxml.omar.server.cache.ServerCache#initialize] - Unable to create test connection for dataSource java:comp/env/jdbc/omar-registry
org.apache.tomcat.dbcp.dbcp.SQLNestedException: Cannot create JDBC driver of class '' for connect URL 'null'
at org.apache.tomcat.dbcp.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:780)
at org.apache.tomcat.dbcp.dbcp.BasicDataSource.getConnection(BasicDataSource.java:540)
at org.freebxml.omar.server.repository.hibernate.RepositoryHibernateUtil.getConfiguration(RepositoryHibernateUtil.java:117)
at org.freebxml.omar.server.repository.hibernate.RepositoryHibernateUtil.<init>(RepositoryHibernateUtil.java:47)
at org.freebxml.omar.server.repository.hibernate.RepositoryHibernateUtil.getInstance(RepositoryHibernateUtil.java:55)
at org.freebxml.omar.server.repository.hibernate.HibernateRepositoryManager.<init>(HibernateRepositoryManager.java:78)
at org.freebxml.omar.server.repository.hibernate.HibernateRepositoryManager.getInstance(HibernateRepositoryManager.java:99)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.freebxml.omar.server.repository.RepositoryManagerFactory.createPluginInstance(RepositoryManagerFactory.java:86)
at org.freebxml.omar.server.repository.RepositoryManagerFactory.getRepositoryManager(RepositoryManagerFactory.java:51)
at org.freebxml.omar.server.query.QueryManagerImpl.<init>(QueryManagerImpl.java:111)
at org.freebxml.omar.server.query.QueryManagerImpl.getInstance(QueryManagerImpl.java:149)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.freebxml.omar.common.spi.QueryManagerFactory.createPluginInstance(QueryManagerFactory.java:87)
at org.freebxml.omar.common.spi.QueryManagerFactory.getQueryManager(QueryManagerFactory.java:49)
at org.freebxml.omar.server.repository.AbstractRepositoryManager.<clinit>(AbstractRepositoryManager.java:61)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at org.freebxml.omar.server.repository.RepositoryManagerFactory.createPluginInstance(RepositoryManagerFactory.java:75)
at org.freebxml.omar.server.repository.RepositoryManagerFactory.getRepositoryManager(RepositoryManagerFactory.java:51)
at org.freebxml.omar.server.query.QueryManagerImpl.<init>(QueryManagerImpl.java:111)
at org.freebxml.omar.server.query.QueryManagerImpl.getInstance(QueryManagerImpl.java:149)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.freebxml.omar.common.spi.QueryManagerFactory.createPluginInstance(QueryManagerFactory.java:87)
at org.freebxml.omar.common.spi.QueryManagerFactory.getQueryManager(QueryManagerFactory.java:49)
at org.freebxml.omar.server.common.ServerRequestContext.<clinit>(ServerRequestContext.java:87)
at org.freebxml.omar.server.cache.AbstractCache.getCacheContext(AbstractCache.java:109)
at org.freebxml.omar.server.cache.ObjectCache.initialize(ObjectCache.java:71)
at org.freebxml.omar.server.cache.ServerCache.initializeInternal(ServerCache.java:100)
at org.freebxml.omar.server.cache.ServerCache.run(ServerCache.java:83)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NullPointerException
at org.apache.derby.jdbc.Driver169.acceptsURL(Driver169.java)
at java.sql.DriverManager.getDriver(Unknown Source)
at org.apache.tomcat.dbcp.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:773)
... 39 more
I try to do everything i saw on internet but the error persist.