Is the key feature of Microsoft's Zune digital media player a dud?

Touting the idea of "connected entertainment," Microsoft unveiled the Zune with a strong emphasis on users ability to share songs with other Zune owners via the device's internal WiFi connectivity.

However, at least one user blog has found that 21 of the top 50 most popular downloads from the Zune service cannot be shared. At launch, Microsoft said that some tracks would be blocked from the sharing feature, but never detailed to what degree.

Both Microsoft and representatives from the major record labels say they are not preventing certain artists from the sharing ability. Microsoft claims it is more a technical issue than a licensing one.