After doing the upgrade I can say that the JDBC which is just a Java .jar file was not needed in the least. The guy at T-Support didn't even know what to do with it. I'm now the happy administrator of a BES 4.1 server with a SQL 2005 (clustered) back-end. And you know what? I sleep better at night.
I'd just like to thank everyone here at the forums who answered my questions leading up to the upgrade.