SoundMax Integrated Digital HD Audio on XP Pro 64

I have a Lenovo T61 6463-4YU that came pre-loaded with Vista Business 32 bit.  I bought this machinefor the Centrino Core 2 duo 2.0 64 bit capability and installed Vista Ultimate 64 bit and all the periperals intall fine.  The problem is that with 3 gb of ram, idling it uses 40% of the ram.  NOT GOOD.

So I decided to go to XP Pro 64 and after much work, searching and installing drivers have all but two things identified and working.  The major problem is that I can't find a driver for the SoundMax Integrated Digital HD for XP Pro 64.

I've tried every driver I can find and can't get any to load, much less work on this machine.  Lenovo tells me they don't support XP Pro 64.

Surely there is some way to get this sound device to be recognized and work in XP Pro 64.

Anyone know how to fix this?

I did some research, and I found that installing the Vista x64 drivers will install and work fine.  The one thing that you might have a problem with, is an included program that runs at startup.  You can disable that using MSCONFIG, and audio will still work fine.  Here is the page I found this information on: http://forum.thinkpads.com/viewtopic.php?p=407865.

Attempting to install the "SoundMax Integrated Digital HD Audio" driver for Vista 64 on XP 64 resulted in an error message: "This Operating System is not supported by this software"