I need to lock Phone during Call

[acidhax]

Well, there is an issue with the Phone Canvas for my Treo Pro (CDMA/QVGA), and it doesn't work well with WM6.5.

I have tried -every- single regedit, and I can't find a single way to lock/turn off the screen DURING a phone call.

I've heard that we could just hit the 'power button', alas, it does not work during calls.

I'm just looking for a simple method of turning off the screen during a call with the default 6.5 Phone Canvas. Help! ;D