> What are the serious problems you ran into with LUAFV?
Some time ago, my Vista configuration was exactly
as you install it - UAC and virtualization turned on.
I made a mistake that I installed (and some time later,
uninstalled) VS 2003 under limited administrator account.
Somehow, the result was hundreds of registry entries (mainly COM objects)
which pointed to non-existant files into C:\Program Files\Visual Studio.NET 2003.
The result was totally weird behavior of Visual Studio 2005
(yes, 2005 vs. 2003). And I had to reinstall the entire OS
to fix that.
It could happen that I uninstalled under different admin
account than I installed it, so most probably it was my own
mistake. The result might be explained by the way how the
virtualization works.
Anyway since then, the file/registry virtualization is the first
thing I turn off after installing Vista, except for
installations for testing purposes under VMWARE.
It’s there only so that apps which write to protected places they
don’t have access to when running as a limited access user continue to work,
by taking the write to a different place.
I know. The concept of virtualization is nothing but hack
into file/registry system to support poorly written
legacy applications 
are you implying that as a developer your filter is not compatible
with luafv, or that as a user you want to disable
it?
I am no longer filter driver developer, I don’t even develop kernel
stuff. So missing driver that is a part of standard OS installation
is not an issue here.
L.