We were told by JDE and confirmed by documents on the Knowledge Garden that Xe will work with SP14.1. See document ID, OTI-00-0168. Although, a conflicting statement is in another document, OTI-01-0052, as follows:
6. The JAS server was not on the same service pack as the OneWorld deployment/enterprise servers. Also, the JAS server was not on service pack 14.2 or higher as required for use of IBM WebSphere 3.5.
We started with 14.1 but have recently upgraded to SP15.