Outlook can be a bit messy when trying to point the App to a mail location. I had a similar problem on my home PC and eventually found a registry setting thats was overwriting /?'YOUR PROFILE'?/Local Settings/Application Data/Identities (as boac mentioned). The setting "key" was called "store root" and it was pointing to an incorrect location on my harddrive (creating a new inbox with Welcome mail every time I logged on)- once I changed the path in here to where my mailbox actually was I had no more problems and picked up all my old mails.
HOWEVER, I would not recommend you go messing around in the Registry if you are a non techie type, but perhaps you could mention it to the guy who did the restore in the first place. Might just point him in the right direction if other advice above fails. (he should really sort this for you for nothing if you had paid him in the first place!)
AGOW