I've had my iPhone 4 on Vz for a year without any problems. In the last couple weeks, it's dropping calls on a regular basis, even though I have at least 4 bars. I almost always use the speaker with the phone on a table or desk - nothing touching it. Usually, I've been talking for at least 15 minutes. There have been calls where it's dropped several times. I've changed cases, in case one of them was interfering with the signal. I've done hard resets. I keep the multi-tasking dock "clean". I've done the *228 thing, both options (just in case). This is increasingly problematic. Research on the web just brings up the Antennagate era; nothing more recent. I'm aware of the left-hand holding issue that covers the lower left side corner where the receptors are. Any ideas what might be causing this?