Is that the legal answer as to what is permitted, or the physical answer
as to what is possible?
Actually, I don't accept it as the legal answer. As someone else said,
"one license (product key) per machine". Well it IS the same machine.
And, further, precisely because it's the same machine, the exact same
hardware "hash" will be generated by the product activation code. So
product activation might well not detect that the same license (product
key) is being installed on two different machines ... because IT ISN'T,
in fact, being installed on two different machines.
It seems to me that installing both the 32 and 64 bit versions of Vista
on two different partitions of the same machine should be legal (one
license per machine ... and there is only one machine). And it also
seems to me that PA shouldn't have a problem with it either (e.g. it
should see the same machine as the same machine, and the product key for
both installations is the same).
And, regardless of what the license agreement says, I'd like to hear
from someone who actually tried it about what really happened, and not
from people who are merely speculating about either what is permitted
(by the EULA) or about what they think should or will happen.