If anyone is looking for a Type 3 JDBC driver, I'm having great success with the JDataConnect driver from NetDirect.
The company offers the driver under a sensible evaluation program: All features work for 30 days, after which you're limited to one concurrent connection and some advanced features are turned off, but otherwise the product continues to work.
To remove the connection limit and get the advanced features back, you can buy the Professional edition for $699 or the Professional Secure JDBC edition for $999 (more if you want "priority" technical support).
NetDirect's free trial version of JDataConnect has been a boon to my JDBC coverage in Teach Yourself Java 2 in 21 Days. Most drivers are only available after purchase, which is prohibitive for readers of the book learning JDBC database programming for the first time.