I have a SBS 2008 domain recently migrated from SBS 2003 using sbsmigration.com tools. Clients that are part of the domain, have difficulty loading https web sites or form based web sites. If I remove the computer from the domain the problem goes away. Once I add the computer back to the domain the problem resurfaces but not as slow. New computers added to the domain do not experience this issue. Client computers are a mix of Windows 7 Pro and Windows XP Pro running IE 7 or IE 8. I have been throught the group policies many times and have not been able to narrow the issue and further. Taking snapshots of the computers before and after do not seem to reveal any additional suspect registry entries. In addition a domain joined computer can access https web sites if you logon to a local account.
The problem started when our ISP cut some lines and then after they restored service this problem continues. We have asked them repeatedly to check the Internet since we are also having re-occuring Internet fluctionations.
We have no control over the firewall but we are putting in our own firewall soon as that seemed to fix the other slow client access discussed in the forums, but this is not the only reason for the firewall upgrade.