I am seeing the same thing. We instal the client with a logon script via GP. 32-bit systems installs fine, 64-bit systems it installs, but cannot gather any information or policies or site assignment. I can manually go in and do discover site within the client, then it works fine. If I run the install script from the command prompt running as administrator, then it installs fine and immediately gathers site/client information. How can the install be automated for x64 machines?