How to disable Push-to-talk button

[aclinml]

Hi, I have a AT&T 8525 that has a Push-to-Talk button. I never plan on using this feature. When I pull the phone out of my holster, it sometimes inadvertently pushes that button and gives me a message about having to pay charges to use this feature.

Under 'SETTINGS, BUTTONS' there is not a way to change this button to something else, or disable it.

I seem to remember someone saying you could modify the Regestry to disable this button. Does anyone have the specifics on how to do this?

Thanks, Mike