The only thing the two computers had in common was that both had Ubuntu installed prior to Vector.
I disagree. They also had you in common and, perhaps, a common download computer. You may have also used the same vector installer (there is an old and a new one....I still prefer the old one).
I suggest, using VL 6.0, you reformat the drive on your experimental computer into three (and only three) partitions, a small swap, a 7 g root (make it bootable) and the rest as home. Except for swap, format them with reiserfs. After partitioning, reboot and again, to use the old installer, don't forget to type "linux" at the first prompt. When you get to the display configulator, do 8 colors and 800 x 600 for the display. That has got to work. If so, go back to vxconf and fix up the display.