Classpath in Manifest.mf

Having problems with defining my Class-Path in a jar.  I can get the jar to run 
if there is only one entry but not for
more entries.  

The jar contines a collection of classes that uses other, external classes to 
work (for example, one of the external
classes is a wrapper class for JDBC connectivity).  It will find the external 
classes if I put them in the jar and will
find it if I specify the classpath on the java command line (without using 
-jar, of course).  However, when I code the
Class-Path entry in the manifest.mf file, it doesn't find the external class.  

confused?  me too... here are some examples (The names have been changed to 
protect the innocent):

// Jar contains all classes, including external wrapper class (this works):
Manifest-Version: 1.0
Main-Class: com.test.OEMDB01
Class-Path: /XYZZY/lib/jt400.jar

// Jar does not contain wrapper class, instead uses a Class-Path to find it
// (this doesn't work):
Manifest-Version: 1.0
Main-Class: com.test.OEMDB01
Class-Path: /XYZZY/lib/jt400.jar /XYZZY/prod/classes

I can use JAVA to run the class if I specify the classpath of the warrper class 
(not using the jar, just plain old
.CLASS files): 
-cp .:/XYZZY/lib/jt400.jar:/XYZZY/prod/classes

This is my first foray into "runnable jars" and would like to use them.  Prior, 
we have kept the directory structure (on
the IFS) and and run the classes from within the directories.

Can anyone help? 

dan