How can I disable voice dialing when the iPhone is locked?

How can I disable voice dialing when the iPhone is locked?

Sometimes it's handy to voice dial when your iPhone is locked with a passcode. You can skip all of the steps required to unlock the phone and call by simply holding the home button until Voice Control prompts you for a command.

This also leaves your contacts open to anyone who finds the iPhone but doesn't know your passcode. To make sure the iPhone will only voice dial when unlocked, follow these steps:

1. Navigate to Settings -> General -> Passcode Lock
2. Enter your passcode
3. Select Voice Dial -> OFF


Followed these instructions as my iphone driving me nuts... and guess what??,,, its still driving me nuts....

I have done all the above and it just don't work.. sure enough it says its switched off but it aint!!! still call to anyone in my phonebook at random...???? crazy

yeah! this is doing the same for me! except it actually just keeps doing it no matter if the phone is locked or unlocked. this means I cant listen to music or charge my phone!!! and its literally annoying me so much.. I dunno if the home button is more responsive, but id love it if apple could implement a app or button that just removes voice dialing/voice control.. really annoying me :(