Transmission slips out of Park on '02 V70XC

My 2001 V70XC AWD only has 55K miles on it and it's been babied, but 2 days ago it starting rolling while in Park while making a faint clicking sound. This does NOT sound good and obviously I need to keep my emergency break on when I park to keep it from rolling (not unlike a manual transmission car). Any ideas? I'm braced for the worst.... Thanks, Adrienne in CO PS. I've also started experiencing the ETM failures people have written about. Twice in the past 2 weeks I've gotten the "performance reduced" message while my car essentially stalled on the highway. Not a pretty picture. I'm thinking right now I should have bought a toyota... aarrrgghhhh!