Problems after creating jdbc driver postgresql.jar 6.5.3

I have followed the steps and created the jar file. I have changed classpath to
use  the current directory and the postgresql.jar file. I am able to compile the
example (JDK 1.1.7) but when I invoke the example I get an error -
Unable to initialize threads : cannot find class java./lang/Thread.

When I use java with no JDBC it works fine  Could someone help with
the installation steps after creation of jar file.

Thanks,
Balajee