You experience some issues when you use external storage media in Windows Media Player 11
You have a Media Transfer Protocol (MTP) device or a Windows Media Device Manager (WMDM) device. The device contains multiple storage media. When you connect this device to a computer, each storage medium appears in the navigation pane of Windows Media Player 11. When you unplug the device, one storage medium is still shown in the navigation pane of Windows Media Player 11. However, you expect that all the storage media should be removed from the navigation pane.
Note: The device and storage media are removed from the operating system and Windows Explorer as expected.
You disconnect an external storage medium from a computer and then re-connect the external storage medium. However, Windows Media Player 11 cannot read the contents of the external storage medium. Additionally, after you reconnect the external storage medium, Windows Media Player cannot sync any content to the external storage medium.
Note: This problem does not occur on an internal storage medium.
For more information on this issue, including potential causes, workarounds, and resolutions, see: Microsoft KB Article KB960490.