Microsoft is blaming an unnamed third party for a mysterious data upload problem on some Windows Phone 7 devices that threatened to boost users' mobile phone bills.
User complaints of the errant data use on phones running Microsoft's OS prompted the software maker to launch its own investigation last week. The company said Thursday it found that a "third-party solution commonly accessed from Windows Phones is configured in a manner that may potentially cause larger than expected data downloads."
"Microsoft is in contact with the third party to assist them in making the necessary fixes, and is also pursuing potential workarounds to address the configuration issue in case those are needed," the company said in statement e-mailed to InformationWeek.
Microsoft says a "low single-digit" percentage of Windows Phone 7 users have reported the data upload problem.
Microsoft did not identify the third party or say whether any users incurred hefty boosts in their phone bills as a result of the snafu. The company also didn't say whether there would be any compensation for users stuck with paying more for the unwanted uploads. Wireless carriers offer data plans on 3G networks that cap the amount of data that can be uploaded and downloaded in a month. Exceeding the limit incurs additional cost.
The latest problem with Windows Phone 7 comes as initial reports indicate sales of phones running the OS have been less than expected. Phone maker LG is said to have reported sales lower than expected, and one analyst estimated only 40,000 Windows Phone 7 devices were sold the first day they went on sale in November. Apple, by comparison, sold 300,000 iPads the first day the tablets when on sale last April.
Microsoft has not said how many phones have been bought by end users, saying only that manufacturers have shipped 1.5 million phones to retailers.