Patch Management Applicable Count Dropping in Altiris 7.1

Hello All,

     Normally when I'm rolling out updates in Altiris 7.1 I will go to the Compliance by Bulletin screen.  Under Vendor choose for example Microsoft and then choose the OS as Windows 7.  I will see all the Winodws Updaters and distribute and away it would go.  In the last few weeks i have noticed the Applicable Count in this view dropping.  We have 345 clients and it has gone down from 345 to 320 to 290 to 260 to 97.  I'm trying to figure out what would cause that number to go down so drastically for Windows Updates.  Not sure if we are having an issue with our agents.  Any thoughts on what could be going on?  Thanks for the help.