Problem installing MS06-033 KB917283 on Exchange 2003 cluster

I have an active/passive Exchange 2003 sp2 cluster on Windows 2003 R2 EE with
..NET 2.0 and this MS06-033 KB917283 update will not install. The error is
something about Access denied and/or stopping services before it errors out.
We're trying to install the updates on the passive node. We tried to
uninstall .NET 2.0, but it had errors about stopping services like IIS Admin
and we cancelled the uninstall (and it appeared to rollback the changes).

Is this update totally borked for passive exchange cluster nodes, or is
there actually something wrong with the .NET config. If we have to install it
on the active node, that would involve a lot longer outage and potential of
total borking of the system, so we'd love to avoid that.

Thanks