Call waiting screen with Nav system freezes

Having a problem with call waiting on my 3G Nav system. When I'm on the phone with someone and another call comes in, a screen pops up that shows "You have an incoming call" with the green phone to answer if you like. If you don't answer that call, it will go to your voice mail like it should for that caller, but the "You have an incoming call" pop up screen freezes on the Nav screen and stays there even well after the incoming caller has hung up leaving no control over the phone at all. The other night I literally had to turn the car completely off and on to gain control of the Nav system again.

Anyone else experience this or know anything about this? Trying to decide how to handle it. Any help would be appreciated. Thank you!

 

Hmmm... well I guess since I'm not getting any replies, it must be my particular Nav system. Lucky me. I'm actually taking my Prius in for its first 5000 mile service this weekend. I'll have to see what the dealer thinks.