There has been discussion for a few weeks now about how Microsoft's new smartphone OS handles expendable storage, with many people reporting that inserting the wrong card can reduce the OS to a crawl.
Now Engadget have discovered that the Windows Phone OS makes permanent changes to a card that can prevent it from being read, written to or formatted on any other device.
Samsung have documented the feature for the Focus, saying that inserting a MicroSD card into a Windows Phone can be considered a "pernament modification" adding ''it will no longer be readable or writable on any other devices such as computers, cameras, printers, and so on''.
Microsoft too has warned of the permenant change, though it's not entirely clear exactly what the OS is doing to the card. Engadget say...
''The Windows Phone 7 operating system treats the SD card as an integrated part of the phone. This is in contrast to other devices, where you can use an SD card to increase the memory available to the device at any time or to transfer files to other devices,'' the page reads.
Meantime, AT&T has warned customers via Engadget that only ''Certified for Windows Phone 7'' microSD cards should be used in Microsoft's mobile devices. The reason, according to the mobile carrier, is that the Windows Phone platform ''requires a certified high-speed microSD card for optimal performance.''
At present, no such ''certified'' cards exist and no indication has been given as to when they will hit store shelves. According to Microsoft support documents, certification comes down to more than just ''a simple matter of judging its speed class.''
''Several other factors, such as the number of random read/write operations per second, play a role in determining how well an SD card performs with Windows Phone 7 devices,'' the page reads.
The lack of clarity over the expandability of Windows Phone handsets could damage sales of handsets from people looking to harness the on-board Zune software to use their phone as an MP3 music and video player.