Hi,
do you encapsulate jar and war file in an EAR file or do you deploy them side by side?
Could you check the deployed war file? If war and jar are bundled in an ear, the war file should containt a "META-INF\Manifest.mf" with e.g. this content:
Manifest-Version: 1.0
Class-Path: myEJB.jar
Best regards
Wolfgang