I also fell foul of this issue, like you I was curious how Windows 8 would run on one of these, then found that Windows 8 does some kind of check and in doing so destroys any chances of having it run properly again. There is a around it but it is not a permenant fix:
When the fizzbook starts, press delete as though you were going into the BIOS
It will then display the familiar message you have got "Sorry, the computer boot certificate.."
Press Ctrl + INS
Then you should have a menu to choose to get into the BIOS setup.
Change the system to date to the year 2000.
Now you can boot into your O/S
Unfortunately as soon as you change your system date to 2013, you have the same problem again!
Until there is a way around it
I personally think Microsoft are liable for essentially bricking a lot of older motherboards, I have seen many people have the same problem online as this. No warning at all is given by MS about this before you attempt to install Win8!