After R5->R6 Client Upgrade, Bookmark Tab does not appear

Upgraded my Notes R5 Client to R6. Upgrade worked without any errors. However, after logging on to the new Client, the Bookmark Tab fails to appear, and the ‘Database Cannot be Found’ dialog screen continually appears. Can access mail, etc, but cannot get Bookmark tab to appear, and have to ‘cancel’ the ‘Database Cannot be found’ dialog to progress.I had numerous Databases in my Workspace, assuming one of these is causing a problem with loading the Bookmark…any suggestions ?