ClassNotFoundException on Class.forName("com.ibm.as400.access.AS400JDBCDriver");

Hello All:
Newbie question here:
I have written a thick client application for win2k that accesses the AS400.   
I am using WDSC 5.1 for development and everything is working fine.
I am at the point to deploy the application to the workstation, however when I 
run the application I am receiving a ClassNotFoundException on 
Class.forName("com.ibm.as400.access.AS400JDBCDriver") statement.
When I export the application as a JAR file, I have included the JT400.JAR file 
within the application JAR.
I have also tried just placing the JT400.JAR file in the same directory as the 
application JAR file, but receive the same error.
The classpath is set to the current directory (-cp .).
What am I not understanding when it searches for the JDBC driver?
Thanks in advance.