I’ve had issues recently with Outlook crashing when I shut it down. Initially I thought this was due to a rogue Outlook Addin (eg I’ve got Xobni, ClearContext, OutTwit and others installed). So I went through systematically getting rid of them. Put the problem persisted.
Finally I found the issue was to do with the actual .ost file being corrupted. The way I discovered this was by chance when trying to clear my Deleted items. Outlook gave me a message informing that the file was corrupt, and even better recommended using scanpst.exe to fix it.
I’d never heard of scanpst.exe but a quick Google check shows it has been around since the dark ages, and has been a regular in the Sys Admin’s toolbox for years.
If you are looking for it you can find it in your c:\Program Files\Microsoft Office\Office 12\ folder or equivalent.
Everything Outlook related needs to be closed down (eg Mobile Device Sync) and then you run it up. It’ll prompt for the ost file and away you go.
Since repairing my file I’ve had no further issues with Outlook.