The problem does not affect Windows Phone 7.5/8 devices
After several months of waiting, Microsoft and Nokia have delivered the Windows Phone 7.8 update as promised.However, it appears that all smartphones that were upgraded to WP7.8 are now affected by a critical bug that will massively take advantage of data usage, thus draining the battery.
Discovered by the guys over at WP7RootTools, this problem only affects Windows Phone 7.8 handsets. So far there have been no reports that the issue might cause huge data usage on devices powered by Windows Phone 8 smartphones.
It appears that when a new application is pinned on the start screen, it makes a request to a server for an icon to be put on live tiles and that website is unavailable, causing an endless loop to try and get that data.
This results in huge data usage and battery drainage. However, as we mentioned earlier, this issue does not affect Windows Phone 7.5 and 8.0 devices as Microsoft made it so that particular app sending requests to a server is set to try again in 30 minutes, so it will not continue to use data.
Windows Phone 7.8 developers made it so Wi-Fi connection enters sleep mode 1 minute after the screen is locked, in order to save battery.
The good news is if users are in Wi-Fi range, this issue with the start screen will take advantage of Wi-Fi connection rather than data network.
Obviously, this will drain the phone’s battery even faster, but at least you won’t have to pay a lot of money on your next bill.
For the time being, there are no known workarounds that might fix this issue, so make sure you check the application pinned on the live tiles is correctly displayed and has the correct icon attached to it, otherwise the phone will continue to use data.