KB922582(fltmgr.sys) problem

When I applied the update KB922582(fltmgr.sys) I experenced the problem
that my filter driver does not decrypt the data in a share folder while

The problem happens when the anti-virus(minifilter) and my legacy filter
driver exist.
The cause is unusual layering of device objects above mrxsmb.

The more strict description is below.

OS: Windows SP2 + KB922582
CPU: x86
anti-virus: minifilter(altitude=329000, Start=SERVICE_DEMAND_START)
My legacy filter driver: Start=SERVICE_BOOT_START
Device Objects layering observed:
mrxsmb (LanmanRedirector)

The observation shows other file system device objects(volume) layerings
are ordinary even if they sit on WebDav. Like

The Irp flow observed at MyLegacyFilterDriver is like below.

<-Create Completion<-
Read(IRP_PAGING_IO) comes from the underlying anti-virus reading
while IRP_MJ_CREATE PostOperation.
MyLegacyFilterDriver can not decrypt Read(IRP_PAGING_IO)
because IRP_MJ_CREATE has not been completed.

Replacing the anti-virus by passthrough sample(minifilter)
and MyLegacyFilterDriver by sfilter,
I also see the unusual layering above mrxsmb.
So,I concluded the anti-virus and MylegacyFilterDriver are not related to
this unusual layering.

Windows SP2 fltmgr.sys(5.1.2600.2180) does not exhibit this symptom.

Thank you.
Ichiro Akimoto