Old FileMaker Servers with Hyperthreading

I Found a problem yesterday that I suspect could be linked to an
incompatibility between an old version of FileMaker Server (v3) and a
hyperthreading enabled processor, and was wondering if anyone could
confirm that this type of problem exists.

Problem Description:
A client has been using a very old database solution that's tried and
true.
It worked like a charm when they were hosting it on an older machine
that was running Win NT4.
They've recently updated some of their equipment, and decided to move
the old solution over to a newer machine.
This machine is an intel based P4 3.2Ghz w/ HT enabled, and is running
Win Server 2000.
They had initially suspected that it could be an incompatibility
between Server 2000 and FileMaker, but I suspect otherwise. The
solution that's being hosted is a runtime build, and seems to only
open some of the files. The odd thing about it is that the files that
do get opened seem to change with each subsequent re-opening of the
solution, and there's no indication of any problems opening the files
within the logfiles that get generated. If we try to manually open
one of the files that didn't seem to open initially, then sometimes it
will open, sometimes it will not.

Unfortunately, due to reasons beyond our control,
we were unable to test this theory by disabling HT.

If you can confirm that this is the problem we're dealing with,
or have any other suggestions, I would be greatly appreciative.

Thanks in advance