Outlook INBOX emails gone back 2-3 weeks after Exchange Server 2010 Restart


Outlook version
Outlook 2007
Email Account
Exchange Server
Hello Diane... You helped me out on a BCM issue several months ago (thanks again) and I'm hoping that you can help me out here again with an issue that's occured a couple of times this year I just can't figure out. Basically, multiple Outlook 2010 clients (Microsoft XP) connected to Exchange Server 2010 (Windows Server 2008 R2) - nothing crazy, very basic network, no add-ins but most/all clients have AVG anti-virus. What happened last night (11/13/13) is that Exchange Server apparently restarted (kernal power failure) around 3:00am. Upon rebooting in the morning, ALL outlook users (including myself) reported lost INBOX emails only going back to 10/28! I tried clearing the offline cache, deleting the account and rebuilding but to no avail. No matter what I try, the last 2-3 weeks of emails from the INBOX only are gone. However, all other emails in all other folders (SENT, for example) are still intact. After rebooting, Outlook appears to be running normally - inbox emails are being retrieved from Exchange and runs like nothing has happened - only that the last two weeks of INBOX emails are no where to be found (one user reported . We run in cached mode and keep OST files on all client computers. I do not believe that this is an Outlook issue - I believe it to be an Exchange issue. It doesn't happen every time and as I mentioned it has happened a couple of times this year. It is very frustrating to say the least. Any suggestions? Thanks, Dave.