Description of problem:


Version-Release number of selected component (if applicable):
RHN Satellite 5.4.1
spacewalk-java-1.2.39-82.el5sat

How reproducible:
always

Steps to Reproduce:
1. Admin -> Task Schedules -> create schedule
2. Create a new schedule
   Name: '13friday'
   Bunch: <whatever>
   Frequency: Daily 1:00
3. Observe: Admin -> Task Schedules (your new schedule is there)
4. Edit a custom quartz format of '13friday' to: 0 0 1 13 * 6
5. Hit a submit
6. Observe: Admin -> Task Schedules (your new schedule is NOT there)


Actual results:
The big red banner appears on a submit:

    Invalid schedule entry: 0 0 1 13 * 6

But the result is stored in the database. What is even worse is that
my 13friday bunch disappears from 'Task Schedules' page!


Expected results:
It should go smooth. 
I need my work done on Friday, 13th (early in the morning).