Vista - File Sharing Between 32-Bit and 64-Bit Vista Ultimate

I have two brand new machines, which both came with Vista Ultimate
installed on them.

One is a 32-bit desktop, that is connected to a router. The other is
64-bit laptop, which shares the internet connection provided by the 32-
bit desktop. All if fine with the internet....

I have file sharing set up on both machines. And when I go into
networking, each machine shows the icon for the other machine as
available on the network.

UAC is turned OFF on both machines. File sharing is of course turned
on on both machines, and password protected sharing is turned OFF for
both machines (The password protected attribute of file sharing MUST
be turned off to successfully share files.)

However, when I click the icon on my desktop to access the shared
files on my laptop, I receive a message that Access is Denied.

And when I click the icon on my laptop to access the shared file on my
desktop, I receive an error saying that there is an error in
connecting with the laptop.

I called Microsoft Support and paid the $59.00 - and here is what I
was told - that --> File sharing between 32-bit and 64-bit Vista
Ultimate machines is NOT SUPPORTED.

Is this correct?? Can this be so???

Can ANYONE help me here??

Any sanity that you might be able to lend to this situation would be
sincerely apprecited!

~ Celia ~