Out of necessity to have a working system ASAP, I installed Ubuntu which has the same problem, but does all the installation from the blue screen which I can see. Now when I boot up, the screen goes blank when GRUB should appear, and stays blank until the graphical part of the boot-up. I will try sumo wrestler's suggestions now in my spare time (rather than out of desperation) and post any solution I come up with, and file a report on debian-boot. The trial and error is a bit time-consuming since I have to go through the initial stages of the install up to the point of reboot to know if it worked or not.
The same problem occurs with the Etch beta 2 business-card ISO. It goes further before rebooting, but then the same thing happens.
