It took a while, but the 7.8 update to older Windows Phone is finally rolling out. Everything isn’t as it should be however with reports coming in of very large data usage since the update.
Apparently WP7.8 changes a few values regarding live tiles and the way that they update. The one who discovered it, WP7 Root Tools, has done some investigating and it appears that when an app makes a request to a server for an icon used in app or some other data and that particular site or address is unavailable it starts an endless loop to try and get the data that is requested. What it does is continuously be browsing the web basically.
In WP7.5 this process was interrupted by the OS and ‘told’ the app to try again in 30 minutes thus putting a stop to the loop of requests. Although it doesn’t appear to be a bug per se in WP7.8, as it comes down to apps making requests to non-existing addresses, but the OS should be handling these kind of exceptions since a server that is temporarily down could also cause the problem.
Mind you, this problem won’t affect all phones. It will only happen when you have a ‘bad’ app. The problem is, you won’t know you have one unless you keep track of your data. So, for the time being; be aware of excessive data usage and keep track of your data usage with the Nokia Counters app.