We have an Exchange 2007 server, fully updated. During weekend updates, several users complained of not being able to use Outlook 2007/2010 due to being "offline". After switching them between Online and Cached they are now working, but can't use the To button to access the GAL. The error is that Outlook must be online to access the GAL. They are unable to use the Reply All function as well. This is limited to only a few users currently, everyone else is working fine.