This is a GP site working within the NHS. We're using Roaming Profiles (mainly because they foisted upon us byb the supplier who provide the main clinical system). Some of our users use the Outlook 2003 client to access a central IMAP service (not Exchange). One of those users periodically "loses" the default outlook.pst file. This has happened so many times now I know how to recover the situation without any problem.
However, I would like to know why. The pst file that Outlook uses for the IMAP service seems to be just a temporary receptacle for mail etc as each time you connect, the Inbox is refreshed and any folders you access are refreshed from the central store on demand.
If anyone has any info on this that'd be useful and I'll be very grateful - I might even be able to stop it happening again.