HTC Tilt 2 - Unable to place calls when phone is locked

I tried pairing HTC Tilt 2 with my Prius 2010. Everything was smooth and the phone was successfully paired. However, when I tried placing a call from the bluetooth, I got a message "Please check your phone" on the navigation screen. My phone displayed this message "please unlock the phone to allow bluetooth connections". After unlocking the phone I was able to place the calls without any issues.

I was able to place calls through the car bluetooth on my old phone (T-Mobile Dash).

Any ideas what could be the problem here? While driving I don't want to pick up the phone, unlock it and then use bluetooth to place the call.

Thanks in advance,
LH

 

Thanks for the pointer jayvee. Looks like there is no good solution to fix this issue.

Thanks a lot.