Java Database Connectivity (JDBC)

Can anyone please tell me what you think about using JDBC instead of Hibernate for small applications?

Here are some facts about my app:
1). roughly 35 database tables
2). using JBoss application server for Connection
3). POJOs as DAOs, wrapped in Session Beans

Hibernate is proving to be a real challenge to develop, mainly because of XDoclet not generating my .hbm.xml files. It works fine for the JBoss server file though. I know I'd figure it out eventually, but I need to decide how much more time to spend on learning it--before our budget runs out. Like I stated above, our applications are very small. So before I start, can anyone tell me:

Am I making a big mistake by using JDBC directly from within JBoss?

Your comments, no matter how brief, would be greatly appreciated.

Regards,
Itchy