Scheduled Task fails to stop

I have a Scheduled Task on a Windows (64-bit) 2008 R12 (SP1) server.
It’s a housekeeping task and I was expecting its first run to take some time catching up on backlog of actions , so set what I thought were appropriate “Stop the task if Runs longer than” on both trigger and general settings (including ‘If the running task does not end when requested, force it stop” ).

1st issue – when viewing the Settings Tab in the ‘Task Scheduler Library’ view – it shows the default 3 days as the time-out setting, not my setting (which comes up if go into edit the task).

The Task run shows with Last Run Result = (0x41306)

The Task History shows

Level       Date and Time   Event ID    Task Category               Operational Code
Information 30/11/2014 19:40:03 329     Task stopping due to timeout reached    Info
Information 30/11/2014 19:40:03 111     Task terminated             Termination
Information 30/11/2014 07:40:02 129     Created Task Process            Info
Information 30/11/2014 07:40:02 100     Task Started                    (1)

…
i.e. the “Stop the task if Runs longer than” did kick in ..

The Windows Application Log shows

Level       Date and Time   Source      Event ID    Task Category
Warning 30/11/2014 19:45:03 User Profile Service    1530        None
Warning 30/11/2014 19:45:03 User Profile Service    1530        None
Of nature “Windows detected your registry file is still in use by other applications or services. The file will be unloaded now. The applications or services that hold your registry file may not function properly afterwards.  
 DETAIL - 
 2 user registry handles leaked from \Registry\User\S-1-5-21-934353228-948777034-184960113-61974_Classes:
Process 2536 (\Device\HarddiskVolume2\Windows\System32\cscript.exe) has opened key \REGISTRY\USER\S-1-5-21-934353228-948777034-184960113-61974_CLASSES …”

Note: 5 mins after the termination (attempt) ; that SID being the account the task was running under.

However the task itself which creates and maintains its own log did not finish until a lot later, appearing to complete successfully.

So more issues:
The History isn’t giving a sensible report; the last entry has Task category = “Task terminated” but it clearly didn’t ( at least not at the indicated date and time ).
The last run result code – nothing to indicate whether this related to the task itself or the failure to terminate.
What can I do to get the task termination effort to be effective ?

The task is a vbs script, run using cscript //b //nologo scriptname .