Newly created Distribution group not showing in OAB

Issue: customer created DL and after a day, it still wasn't showing up in the OAB. Customer is running Outlook 2010 in cache mode
Resolution: Advised customer to download address book, but that didn't work
customer closed outlook completely. deleted *.oab files from this directory:C:\Documents and Settings\User Profile\Local Settings\Application Data\Microsoft\Outlook:
customer restarted outlook and was able to find the distribution group in the address book