Capture Job Release Date

The goal is to capture the Release date when the Job status is changed in the "Job Status Maintenance" screen.

I have the following code in a BPM.
JobStatus.MassUpdate
------------------------------------------
FOR EACH ttJobHead EXCLUSIVE-LOCK:

FIND FIRST JobHead where JobHead.JobNum = ttJobHead.JobNum NO-LOCK NO-ERROR.
if AVAIL JobHead THEN DO:
ASSIGN ttJobHead.Date10 = TODAY.
END.
END
---------------------------------
The condition is for whenever the field JobRelease changes.

It appears I'm going to the correct place with the BPM but I receive an error message when making the changes in that screen.
---------------------------------
Exception caught in: Epicor.Mfg.BO.JobStatus
Error Detail
============
Message: Record has been modified by another user and couldn't be updated. Please press the Refresh button and re-enter your changes.
Type: UpdateConflict
Program: core/BizRuleEngine.p
Method: Main-Block
Table: JobHead
Row: 0x000000000021e723
Field: Date10

Stack Trace
===========
at Epicor.Mfg.Proxy.JobStatusImpl.MassUpdate(JobStatusDataSet ds)
at Epicor.Mfg.UI.Adapters.JobStatusAdapter.MassUpdate()
------------------------------------------------
Any idea what is going wrong here?
All suggestions would be appreciated.

Thanks,

Dave
Xybix
8.03.407C P