If you ever have issues when re-installing office on your mac by getting this error
There is a problem with the Office database
Office might be unable to access the database or the database file might be damaged. Without the database, you might be unable to use the Address Book, Scrapbook, and other features that store your personal information.
To rebuild the database, open Microsoft Office 2008/Office, and then open the Microsoft Database Utility. For more information, open the Database Utility application, and on the Help menu, click Database Utility Help.
The section below will help you solve it!!!
Deleting “Main Identity” only did not help me. Here is how I solved
1- Deleted “Microsoft User Data” folder under Documents
2- Deleted all com.microsoft.* under ~/Library/Preferences
3- Deleted Microsoft folder under ~/Library/Preferences
I then re-ran Office Setup Assistant, and problem solved.
via Microsoft Office 2008 Database Problem – The macosxhints Forums.