KB918176 should be available shortly via the following link http://support.microsoft.com/?id=918176
This article discusses a problem with alert suppression not taking effect when using managed code to create events and a event rule which creates state based alerts in response to those events. This problem only occurs when creating such events/alerts for non-Windows computers.
A hotfix for this issue is available from Microsoft Product Support Services (PSS) if you are seeing the symptoms described in this article.
Please see the article for more details when available.