Believe me. I understand, my friend. You have to do what is necessary to keep the line of communications open, especially in business. Also, you mentioned that the geniuses at the Apple store did a full restore and sent you on your way. I'm wondering if they just did a restore by using your last backup instead of a full reset and restore as new. The latter is definitely recommended when troubleshooting because you never know if something installed via a third party app is the culprit. By starting completely fresh can help single out such apps, if applicable.
You're right, they did a full reset and restore. It was as if my phone was brand new, out of the box. Alas, no joy. I took the phone home and tried it out with no new apps installed, and it still did the same thing. To me, that proves that the issue is network related. I'm thinking that maybe a network extender is my only remedy.