Solving a Microsoft Communicator Address Book Syncing Issue

Microsoft Communicator 2010 ― I have a problem with systems that are using Microsoft Communicator 2007, where they are unable to synchronize the address book. This of course makes searching for contacts nearly impossible and is quite annoying. I Googled around and found all sorts of people with similar issues, but it appears the same symptom can be caused by many things. I’m going to describe what I did to fix my particular situation.A really important detail in my situation, is that this was only affecting users that were[...]