Exception referencing a class from a jar file in IS service


I am trying to reference a class from a jar file in a Java IS service.
The jar files is places in the IS packages in the code\jars folder.
The service compiles, but when I run the service I get this exception:

2010-09-17 10:22:55 CEST [ISS.0028.0048E] Failed to read class ***.core.service.base.CoreSOAPEndpointClient from input stream

What could cause this problem?
Could it be a compiler level problem?

Than ks

My problem was I was still missing some jar files and references by the that class.