iOS 8.0.2 Incoming Calls Fail?

I recently updated to iOS 8.0.2 on my 4S and everything seemed to be going great, as usual. I was able to log into my favorite Social Media Apps, read my news, check weather reports, work either on wi-fi or 3G -- no problems. However, I realized pretty soon that incoming calls through Vodafone weren't coming through.

Also, in many cases while trying to make an outgoing call, the first try would "Fail" (no explanation -- just the word) and I'd have to try a second or third time, when the call would go through.

Text messages too began to reach my iPhone late. I have no idea why this is happening. People are complaining that I don't pick up their calls or answer texts, but the phone logs don't indicate any missed calls or texts.

I am in signal range (often at home) always. I even tested it by asking my kids to call me while we were standing next to each other, in a place where we all get a five-bar Vodafone signal. We found that, if the caller tried repeatedly, a call would sometimes come through.

That this is not confined to Vodafone (so nothing wrong with my provider) is evident from the number of complaints on various forums, including the Apple user forum (see https://discussions.apple.com/thread/6571003 for one instance.)

Again, that this couldn't be the fault of my iPhone 4S -- which has worked flawlessly on all updates thus far, including iOS 8 -- appears to be borne out by the fact that many other users of even newer iPhones have documented this on other forums as well.

Apparently the solution doing the rounds is to "hard-reboot" (is that even a term?) the iPhone by holding down the Home button and the Power button on top. I just tried this and am now waiting to see the result. Hope it works.

Anyway, it is just three days until Apple, hopefully, releases iOS 8.1. Again, hopefully, this will solve our niggles ... for now.