Description of problem:
Clicking on shcheduled operation (group operation on managed servers - eap6) ends with Failed to fetch GroupOperationSchedule error.

Version-Release number of selected component (if applicable):
Version: 3.1.1.CR1
Build Number: 3219830:ad1ab7d

How reproducible:
Always

Steps to Reproduce:
1. eap6 is running in domain mode and is imported to inventory
2. create a few managed servers (EAP Domain Controller->inventory->create child)
3. schedule group operation on group of managed servers (right click on 'managed servers' under EAP Domain Controller resource in left tree - groupOperation.png), choose 'in the order specified below' in section 'Execute' and click on schedule
4. click on scheduled operation in EAP Domain Controller->operation->schedules 
  
Actual results:
error.png

stack trace from message center:
java.lang.RuntimeException:[1346433052142] javax.ejb.EJBException:java.lang.NullPointerException -> java.lang.NullPointerException:null
--- STACK TRACE FOLLOWS ---
[1346433052142] javax.ejb.EJBException:java.lang.NullPointerException -> java.lang.NullPointerException:null
   at Unknown.anonymous(Unknown Source)
   at Unknown.anonymous(Unknown Source)

Expected results:
display operation schedule