Right, I'm typing this from the same CD I've attempted to use - running as a LiveCD on an i7-740QM @ 1.73GHz (quad), 8GB DDR3 1333MHz, GTX460m 1.5GB GDDR5.
It's definitely the server. So far I've removed the HD5450, solved one problem, and disconnected my storage drive (leaving the system drive there) which granted me 5 more seconds of boot time before dying still.
Using a 10.04 LTS disk I have been able to boot all the way through to the live cd "splash". This stays on for 30 seconds before the screen just goes black - it's on, but it's not outputting. Same for verbose - it gets to "Setting sensor limits" and then the screen clears to black.
BUT: With 10.04, everything is still responsive - it hasn't died, it's just stopped displaying...
This is an ATI X1250 integrated. PLEASE PEOPLE!!