We are having a strange problem with our Outlook users who are using Outlook in Cached Mode. The Global Address List does not accurately reflect additions or subtractions of users even after 48 hours and manually updating.
After troubleshooting the problem, I found the problem to be only with users who are using Outlook in Cached Mode because users that are not in Cached mode see the changes instantly once I refresh and rebuild using Receipient Update Services.
The only way I can get Outlook Cached Mode users to see this change is to go through the tedious process of deleting all of the *.OAB files on their computer, and also adding the following registry entry
Windows Registry Editor Version 5.00
It just seems like there is something buggy or wrong here.