While you didn't mention it, I know of issues like this. For 2003 you need the latest patches and maybe to unplug the PDA.
I am using Outlook 2003 and Windows XP Home SP2. I have a problem with Outlook loading in Windows Taskbar. It doesn't load until I open up Outlook for the first time and it will not unload. This causes problems in shutting down the PC, creating backups using the Outlook Backup utility (it won't work with Outlook open or when in the taskbar). Any program requiring Outlook to shutdown for installation hangs up and I cannot close it from the taskbar: I have to shutdown thru Task Manager. When I do so, Outlook wants to start up in safe mode when I open again or will not start again at all.