Endpoint slows computers to a crawl

Just installed Endpoint on 24 pc's over the weekend. It brought every one of them to a slow crawl. Opening Outlook 2007 = 1:47 secs, Clicking on Contacts = 2:12 secs, open IE 8 = 1:10 secs. This was obviously not acceptable to our client so after adjusting the settings and getting nowhere, we uninstalled Endpoint and re-installed Business Edition. Performance returned to normal. Any clue as to why the Endpoint would bring every computer to a crawl? Did I overlook or dismiss an important requirement for the installation?

 

Since v4 does not support IMAP scanning unlike v5 / Endpoint, could you check if disabling IMAP scanning make a difference? Especially if they actually receive email via IMAP.