ECO change been updated unrelease Job even is future effectivity date

 Hi

I have implemented ECO as below:

ECO: 12345
ECO Date submitted: 7-JAN-2010
ECO Implemented Date : 7-JAN-2010
Effectivitiy date: 30-JAN-2010
Disable : Item A
Add :       Item B:

I have 2 Discrete Job with status unrelease:

DJ: 1000 & DJ: 1001.

After ECO was implemented, system auto apply the 2 unrelease job as below:

Disable : Item A
Add :       Item B:

even ECO has been entered effectivity date is on 3-JAN-2010.

Any idea why system does not consider the effectivity date?

Please advise. Thanks

Regards,

Alvin He