Multiple User Profiles/Desktops Created

We are running into a problem with several different XP machines in which the user logs on and when they try to access their Outlook mailbox they have to configure their mail again, even though their mail had been configured. In looking at the harddrive I see that under the Documents and Settings folder the user is being given several different desktops, such as user; user.000; user.001; etc. This causes problems such as their desktop shortcuts and icons have to be moved or copied, and some applications (such as the ActiveSync for their PDAs) won’t function properly because its looking for the original user path. Any ideas?