I have a recurring issue with Outlook 2007 completely locking up while editing a message. The environment is Exchange 2003 and the client OS is both Windows 7 64 and Windows XP 64. It seems to happen more often on the Windows 7 machines. The symptoms are usually the same. When editing a message, usually very early in the process, Outlook 2007 continues to draw it's windows but the mouse just disappears when hovering over any of them. Outlook.exe uses 100% of one core and stops responding to all inputs.
I've googled extensively and tried a few things, like deleting and recreating the MAPI profile, but nothing has done any good. I don't know what to try next.