Nav system has dropped map data and previous destinations..can i reboot/fix?

Haven't found an answer to this in previous posts. I don't mind so much when my 2006 Prius deletes my 'previous destinations' every so often (maybe every year or so), but now i'm really annoyed because it seems to have lost the data that allows me to input a destination.
For example, i still see the maps, but if i want to find "1865 Walnut" in my town, it doesn't know of it's existence and is only able to find that street in another state (Pennsylvania for some reason, and i am in California).
At the same time, i noticed my previous destinations were gone - though my marked locations still exist.

Any suggestions? Can i reboot the system somehow? Thanks.