Switch Desktop Software to new Outlook PST


For the new year I created a new Outlook 2010 pst file.  My BlackBerry Desktop software had been set to sync with the previous one.

I tried to add the new one, set it as the default, and remove the old one, but the pop-up indicated that all the data associated with the pst I was removing would be erased from my device!

OK, so I copied the data (calendar, tasks, contacts, notes) from the old PST to the new one, and BB Desktop Software still won't let me choose the one, new PST.  With both folders mapped, the system now wants to double the contacts, appointments, etc.

I did this last year and was able to make it work, but can't remember how.

How do I get the device to sync with just the new PST and remove last year's?