9.1-903 JDBC 3 Download

Today I downloaded the postgresql-9.1-903.jdbc3.jar from the website,
http://jdbc.postgresql.org/download/postgresql-9.1-903.jdbc3.jar. The
jar once installed in replace of the older version crashed the app.
on Class.forName(org.postgresql.Driver).

Exception in thread "AWT-EventQueue-0" java.lang.UnsupportedClassVersionError:
org/postgresql/Driver : Unsupported major.minor version 51.0
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(Unknown Source)
    at java.security.SecureClassLoader.defineClass(Unknown Source)
    at java.net.URLClassLoader.defineClass(Unknown Source)
    at java.net.URLClassLoader.access$000(Unknown Source)
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClassInternal(Unknown Source)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Unknown Source)

Upon returning to the older version, 9.1-901.jdbc3 or use of the 9.1-903.jdbc4
version the app properly loads the driver as expected. Could someone on the
list please validate that the 9.1-903.jdbc3.jar from the project's website
possibly gives similar results when used.

danap.