Third-party software was the cause of phantom data uploading over 3G experienced on some Windows Phone 7 devices, Microsoft has said.
A small portion of users had claimed the mobile operating system was sending unidentified data over a 3G data connection, unbeknownst to them.
Some said it was sending the data over 3G, even when connected to a Wi-Fi network.
One noticed that up to 50GB of unknown data was being sent over this connection.
According to a Microsoft spokesperson speaking with Seattle PI, a third-party solution “commonly accessed from Windows Phones” is configured in a way that potentially causes larger than expected data downloads.
The spokesperson said they contacted the unnamed third party to help fix the problem and they are looking into workarounds to address the issue.