issue is described in Unable To Register EBS WSRP Producer In Webcenter (Doc ID 1567314.1)
The root cause is the current implementation of JOC within Oracle Applications which initiates JOC within the Applications rather than at the J2ee level.
Bug 9850207 - DOC: PORTLET PROVIDER REGISTRATION ISSUE WITH OACORE PROCESSES > 1
There are two workarounds for the issue described
1. Reduce number of J2EE OACore (OC4J) porcesses to 1.
2. Add to the OACore J2ee startup parameters -Doracle.ias.jcache=true
Note: This changes have to be done in the Oracle E-Business Suite portlet producer installation.