Several times over the last couple of weeks my 3GS has had prolonged periods of "No service" even though I usually get signal in the area. The other day, desparately needing to send a text and tried to send one - it went through. I then receieved a reply and sent another, all the time with the phone showing "No service". I restarted my phone and then had 4 bars. Is this a bug? Anyone else had this?