If you disable and then enable a keyword filter list that you have created in Microsoft Forefront Security for SharePoint, the list does not detect keyword filter matches.
To resolve this problem, install Microsoft Forefront Security for SharePoint Service Pack 3 (SP3). For more information, click the following article number to view the article in the Microsoft Knowledge Base:
967995 Description of Forefront Security for SharePoint with Service Pack 3
To work around this problem, use one of the following options:
Restart Forefront Security for SharePoint and the SharePoint services.
In the Forefront Server Security Management Console, turn off keyword filtering, and then turn it back on. To do this, follow these steps:
Click Operate, and then click Run Job.
Click to select a scan job to disable the keyword filter list.
Clear the Keyword Filtering check box, and then click to select the box.
Steps to reproduce the problem
In Forefront Security for SharePoint, create a keyword filter list by using the steps in the following user guide: