In that case the whole OAB is being downloaded again.
I'm having an issue with Exchange 2010 and Outlook 2010. This problem started after we flattened our domain. We migrated all the users from the the sub to the top using the ADMT and then we took down sub. To be sure, does OWA (which uses live information) reflect the GAL correctly? The first thing you should do is on a test workstation, is delete the *files.
In Cached Exchange Mode, Outlook 2007 & 2010 downloads a local copy of the Global Address List (GAL), but only updates it every 24 hours.
In order to reflect any changes or updates made to the Global Address List, you can force Outlook to download a new copy of the GAL.
Please visit the document on How to turn on or off Cached Exchange Mode for (Outlook 2010, and Outlook 20).
In order for some GAL entries to show up properly you may need to turn off Cached Exchange Mode.
I created a new OAB with both distribution methods this morning.
I ran the commands you recommended and tried it about 4 hours after that. As another way to troubleshoot the problem, I created a new profile for Outlook.
In this guide, the relevant timings are explained and instructions are given in how you can directly force an update and resync, which can be very handy when troubleshooting or when you work in an Exchange environment which sees a lot of user mailbox mutations.
This means that in the worst possible scenario, an update to the Address Book won’t become available to the user until 48 hours after the change.