I see the problem. We may need to re-release B4 so that this doesnt happen to everyone...
Open "My Computer" and browse to your main PokerTracker 3 directory then go Data/Config. Open "PokerTracker.cfg" in Notepad. Scrolls down and look for [Tabs]. Change the following lines to:
[codeif4]Last:WindowMain=0
Last:WindowImport=1[/codeif4]
File->Save, Start PT3. Before switching any tabs, immediately create a new database and set it as your default/active database so that this does not happen again.
Best regards,
Derek