hi!
we have the same problem, but with only a few computers. our operating systems have been upgraded to both vista ultimate and business. when we take the laptops out of the office, then they speed up again and outlook doesn't freeze. i thought it may be our server, but majority of our laptops are fine. we believe that it has to do with the number of emails sent/received a day on these laptops, or the fact that BCM is used so much.
would love to learn if you guys found a resolution.
pedram