update: i took the good disk from the bad machine and put it in the good machine with the bad disk.
andrey ps: two things worth mentioning: i had optimistically set the vga resolution to 1600x1200 which didn't work for this particular nvidia card. it worked when i toned it down to 1280x1024. the latest pcf config file has 'realmode' defined in the 'misc' section. this prevents it from being started at boot time and aux/vga complains that there's no /dev/realmode during its vesa initialization routine. i moved it to the 'link' section. i see that the newer pc* config files on sources have it at the right place, so i guess i was just unfortunate to burn my cd in the brief period where the kernels were borken.
