7.0 - 7.2 upgrade, org.postgresql.Driver Class not found

I am trying to upgrade a working application from Postgres 7.0 to 7.2.

I have downloaded the pgjdbc2.jar and installed it next to the old jar.

When I try to run with the new jar, I get a class not found exception:
org.postgresql.Driver, when I switch the path back to the old driver I
don't have this problem (but do have others due to the mismatch between
the jdbc jar version, and thet Postgres version.)

I have tried to look into the jar with three different jar/zip viewers,
none of which seem to think pgjdbc2.jar is in a valid zip/jar format.
The viewers are not the latest, but they have all looked inside other
jars in the past. I have downloaded the jar twice and they compare ok.

I get the same Class not found with the older /pg72/jdbc7.1-1.2.jar as
well.

The jdbc7.1-1.2.jar is the one that works. (For the Class not found
part)

I am running RH Linux 7.2, Apache 1.3.14 ApacheJServ/1.1.2/ GNUJSP 1.0
wrapper (yes I know, long in the tooth, but they were to be upgraded
after the Postgres upgrade.)

We are using the IBM JVM 2-13 which I believe is a Java 1.3 VM (I'm not
sure if the JIT compiler is enabled)

Any thoughts would be most welcome.

Harrison

huhl(at)email-services(dot)net