Update - I have good news for you and bad news for me.
Motherboard - Asus K8V-X (via K8T800) - Avoid this and via chipsets ref MythTV and other PVR websites.
I got another H/D and I installed xp on the computer. I found it was 'flaky' even with the windows software. Not good. I tried it in my other computer, also a Asus K8V-X. Same problem. I could only find a pvr-150 locally, so bought it. Same problem in both computers. After checking mythtv and other pvr mailing list archives and forums I found out there are issues with various VIA chipset motherboards - Great ! ?#$@$?#
Tested it in an asus p4s333 (sis 645 chipset) - both worked fine in XP - Tried plutohome - works fine as well.
O.K. - some notes.
The plutohome server is designed to connect to the internet and be on all the time, hence the Two interfaces and the firewall.
But for many people who are testing, this is a problem. You can't (easily) have Two DHCP servers going at the same time so if you have a real firewall or firewall/router the box, then you have an initial problem you MUST solve.
Assuming you are going to be turning plutohome on and off whilst testing, turn off any dhcp server in the firewall/firewall/router and set your other computers to static IP addresses with the appropriate netmask, GW and DNS servers.
You will know when you try and boot a pc as a media server as it will likely pick up the from both dhcp servers and you will get an IP in a different subnet (assuming your other subnet IS NOT also 192.168.80.x). Most are 192.168.0.x or 192.168.1.x
NOTE: you will need a switch for the 192.168.80.x subnet as well. Devices you want to control/use need to be connected to this switch
During the install, pick 640x480 resolution (I used 60HZ) - I had problems with the video etc. (you can change this later after you login to the web setup)
Also DO NOT accept the default 'UI ' that is for newer gforce 65xx graphics cards, otherwise you will end up with a grey screen.
I tested one of those useless K8V-X's as a media device and it worked fine.
My Gateway MX7515 notebook (Marvell chipset sky2 driver) doesn't get past init 2 unfortuantely :-(
I'm going to compalin to asus about these motherboards and find the receipts, as I have found out that they have 3-year warranties.
The GC100 has arrived and is installed. It's a slow process (I don't have much spare time) but hope to get the A/V working, then x-10, and the asterisk, and later, the CCTV system. I'll be using the spare H/D for any new releases as I don't want to hose a working test system.