Hmm, so this explained my 3G data overage last month. I have 6GB/month of data, and usually I'd be using around only 700MB. But last month my iPhone 4S (running iOS 6.0) consumed nearly 8GB in total, resulted in quite some overage fee.
Last month I moved and didn't have an ISP at home for the first 3 weeks or so. I set up tethering on my phone and a 5GB data plan. Yesterday I got a notice that I was over my data limit. I haven't done a whole lot of web surfing in the new house, but I have listened to a ton of podcasts using the Podcast app which I have never done before.
So if I just blew through 5 GB of data in 2ish weeks and the only thing different was using the podcasts app...
(I did watch 3 episodes of walking dead on Netflix which obviously contributed to the data use, but a 45 minute episode can't be that big)
Interesting. I was using the Podcast app too, which I believed was the reason for the data overage. It shouldn't be, though. A few podcasts are definitely under 1GB. This AV Foundation Framework issue seemed to be the root cause.