Filter Drivers and Windows 2000 Clustering

I came across a Microsoft KB article Q250355: Antivirus Software May Cause
Problems with Cluster Services.

In the article it refers to some filter drivers “may not understand the
shared disk model”.

Does anyone have any more information on this? I.e., what does a filter
driver, such as filemon, need to do to be “aware” of the shared disk model.

I am sure many others besides me would be interested in this.

Many thanks.