Stop me if you've read this before, but yet another music-download site is shutting down its "digital rights management" machinery, leaving customers with no way to play these songs on a new computer -- or, if they upgrade their operating system, on their existing PC. This time, the offender is Wal-Mart. But unlike such earlier vendors of DRM-ed music files as Sony, Microsoft and Yahoo, Wal-Mart is giving its customers far less notice. As the...Please click on the title to continue reading this entry. ...