Just thought I would report the following. I prepared a 16gb usb drive using NBI 1 and a retail Leopard 10.5.6 cd. I used it on a mini 10v with A6 and a 160gb hard disk. I got past the apple and the wheel underneath. Then I get the purple star screen and a never ending slowly rotating (clockwise) color pinwheel. After a couple of attempts, windows xp became broken so I could not boot up without using odd combinations of unix commands.
I got a copy of snow leopard and prepared the usb stick exactly the same way. This mini that would not boot into windows was reshaped into a mac with no problems whatsoever.
For those of you out there who have had problems with Leopard when installing on a 10v, try doing it with Snow Leopard. This is only a sample of size one but things might work the same for someone out there.