SecurityCenter/AntiSpywareProduct Status won't update after Vista   

On Vista(without SP1), if user turn off the MS Defender, the WMI class 
AntiSpywareProduct(root\SecurityCenter) will show product enabled = false;
but after SP1 is installed, the status won't change according user's 
settings. 
Any one help me?
Thanks

date: Tue, 22 Jul 2008 17:52:08 -0700   author:   Bruce Chen