Did you find a resolution to this problem?  I am experiencing the same.

Vista x64 with Office 2007

I had this problem and looked through all the forums without success,
but finally found a solution. I have an Access database with linked
tables that connects to an SQL server elsewhere. It worked on Windows
2000, XP, and my 32 bit Vista laptop, but not on the 64bit Vista
desktop. I tried setting up a System DSN through ODBC drivers in the
Control Panel. The test worked there, but when I opened the Access file
it said it couldn't find the ODBC driver and therefore I couldn't open
the linked tables.  
The solution (found by carefully following instructions in the only
Access manual I could find that even had ODBC in the index) was to set
up the driver from within Access 2007, using Get External Data/More/ODBC
database/linked tables. That opened up the same window you get from the
Control Panel. It would not let me set a Machine connection, but did
permit a User (file level) connection. I just had to click on the SQL
server driver and the usual set of questions appeared.  When I finished,
the connection worked. Once the connection was established, it also
shows up as a User DSN in the ODBC drivers via Control Panel.
I think the problem is that 64 bit Vista has another level of
security, so that it only lets you make a connection that is specific to
the file, and by doing it from inside Access, that lets the OS know that
you're dealing with a 32 bit application.
There is a bunch of stuff in other forums about how there are two
different Access drivers in different directories in Windows. I found
both of those on my computer, but didn't have a clue what to do with the
information. If you are making any kind of a connection for an Access
database, the solution seems to be not to go searching for apparently
missing drivers but to just establish the connection from inside Access
2007, where you get the old familiar list of all sorts of drivers. My
control panel User DSN window also shows a phantom Access 2007 driver
that it says doesn't exist, but all the drivers are there if you start
from inside your Access database.