I noticed that turning WiFi on and off makes the lock sound (both on and off). WiFi works fine, and it makes the sound whether I turn it on from Settings or SBSettings. I tried restoring but it still makes this sound. iPhone4 (32GB), jailbroken 4.0.1. My other iPhone4 (16GB) doesn't make this sound and it too runs 4.0.1 jailbroken with the same Cydia apps installed. Anyone experience this 'issue' before? Is there an option to turn off the WiFi sound somewhere that I missed?