Sprint TP2 Registry Settings Reverting?

[quarky42]

I keep disabling the stupid FlightMode sound effect using the "EnableSound" registry key and it randomly reverts back to being enabled.

(Setting the key to 0 disables the sound effect, and this will last anywhere from a week to many months. Recently I had gone for 4 months with that stupid sound effect being disabled until today when it started again and sure enough the value was back to 1.)

I've tried deleting the PhoneOn and PhoneOff sound effect from Windows directory using TotalCommand and I've tried overwriting it with a silent sound file... and even those revert back.

I've not flashed the phone or installed anything else recently. Somehow Sprint or HTC has something running that is reverting these settings and files back. VERY annoying! Is there a service or something that I can disable?