Nogginsaked

Ask yourself why the Mac OS cannot be installed on any Intel motherboard
with a core duo processor?
The advantage of the Mac is a vertically integrated system with exceedingly
limited hardware and software choices controlled by a single vendor.
The disadvantage of the Mac is a vertically integrated system with
exceedingly limited hardware and software choices controlled by a single
vendor.
If the Mac suits one's limited needs and one is willing to pay the Apple
premium all is well.
Apple has restructured what would be the BIOS in a Wintel program so that
calls from the Mac OS cannot be interpreted on a generic Wintel motherboard
without an intervening software layer. While software to do this is out
there on the web it is difficult to install and no commercial vendor can
supply that software without encountering Apple's core of attorneys. If
various web sites are to be believed people have the Mac OS running on
hardware that is light years ahead of anything Apple offers or on the same
hardware at a fraction of the price of Apple manufactured machines.
Windows cannot run on a Mactel without a software layer interpreting calls
from the OS to what is the BIOS/chipset on the Apple motherboard. Therein
lies your rub. I am surprised you got the thing to boot at all. Bootcamp is
the software layer that alters Windows BIOS calls for the Mac chipset. Apple
is not supporting Vista64.
It is not clear that Apple even supports 64 bit programming on their own
platform but that is beside the point.
If you have 64 bit video production software that is Windows based and will
run on Vista 64 you should have done the math: you could build/buy a Wintel
system with better gear than Apple deigns to sell at a fraction of the price
of Apple hardware.