RioCar 20GB 2.00-beta7.

Has anyone else experience this. I pulled the unit out before shutting down the car. When I came back, I plugged the thing in and I got a message saying Hard drive not found, contact support. I started driving and let the thing sit for 2 minutes, then plugged it into the sled, and it worked fine. This happened again on the same day. I did the same thing, and it worked. Then, I started shutting the car off, waiting for the unit to shut down completely (I set it to 10 sec), then removing the unit. Now it works perfectly everytime I plug it back in when I do that.