iPhone text message chiming in silent mode

Midway through my UMN lecture on computerized physician order entry my 3G iPhone started pinging. My 12 yo was texting me.

Thing was, the phone was in silent mode (red dot on the ring/silent switch). It's not supposed to chime. It wasn't ringing when I tested however, so I knew the switch was working.

I shut down and restarted the phone and changed the text message sound. Of course power cycling makes sense, but the I had a reason to change the text message sound too. That comes from my OS X experience; sometimes changing settings will fix a corruption problem.

That worked. The phone no longer chimes when in silent mode.