unable to modify call waiting tone

[sfaguy]

hi there,

i wanted to change the default call waiting to my own sound, so

1. i created my own sound ct-call-waiting.caf
2. then i SSH to iphone /Systems/Library/Audio/UISounds
3. then i uploaded and replace ct-call-waiting.caf
4. i tested it using cyberduck and it has my own sound

then i rebooted my iPhone, tested the call waiting sound, yet it still plays the old one? did i change the right file???

for the record, i was able to modify and use my own ringtones for calendar alarm as well as when i receive a voice message. unless ct-call-waiting.caf is not the correct file for call waiting.