Bluetooth phone settings disappear?

I have no problems registering my Nokia 6255i with my 2006 Prius and talking hands free. But, every time I turn off the car, the next time I get back in, it will not autoconnect and all of my settings are gone. It does not show my phone that I previously registered. I'm beside myself trying to figure out what I'm doing wrong. Other blogs say to push autoconnect, but I can't do that because of my setting disappearing. Please help if you can!!