Ok, I believe this proceedure has fix my phone as well as my wife's and several others.  I have been told that having call issues on your phone could be OS related.  So originally I did a RESTORE to the phone.  A gentlemen at the Apple store told me it's like reloading an OS on top of itself.  It sometimes helps...but isn't the best way.  What you really want to do is wipe the phone clean (format the memory) and then place a fresh copy of the OS onto the phone and then reload your data.

They call this the "RECOVERY" mode.  To do this, and fix the issues on your phone here is what to do:

1. Connect your iPhone to your computer and sync it...and leave it connected to your computer and iTunes.
2. Now, using a paperclip, pop out your SIM card.
3. Turn your phone off.
4. Once it is off...push your SIM card back in.
5. Now, while holding the HOME button (button on the face of the phone at the bottom)...press and HOLD the power button on top until you see the Silver Apple Logo.
6. Once you see that log let go of the power button on top, but STILL keep holding the HOME button.
7. Once you see the logo change to a USB cable and CD, then you can let go of the HOME button.
8. iTunes should now recognize that your phone is in "RECOVERY" mode and ask to recover and restore your phone.
9. Follow the directions on screen to complete recovery, then restore, and then do a sync to make sure all of you data is back on your phone.
10. NOTE: you may need to do a second sync to make sure that everything is back on the phone.

Once you do that you should be fine and issue free on your iPhone.

Enjoy!