Active Directory slow to pull list.

We ran the NT4 domain to W2k migration in our lab. We now have a w2k DC, NT4 BDC, and a w2k DNS server in our lab running mixed mode. We also now have 1800 AD objects. The problem is it takes forever to build that list when we want to do simple things like add a user for delegation or add a user for a NTFS permision. Is there a way to have this information cached so the list in the Add users, groups and computers window builds quicker.