Sorry if this has been discussed before but I did my best to search and nothing came up about this: Woke up this morning to unplug my iPhone 4, which was charging overnight. Checked my email then sent a short text message, but I didn't hear the usual clicks and other sound effects. Checked the volume and other settings but they were all set to 'sound on'. Decided to reboot and wala, the sounds came back on. Weird. Has anyone experinced this?