If media-libs/libdvdcss-1.0.0 is installed and use has "decss" and "dvd" set, mplayer will be unable to decrypt encrypted dvd's. to fix, change: decss? ( media-libs/libdvdcss ) in the mplayer ebuild to decss? ( =media-libs/libdvdcss-0.0.3 ) or decss? ( =media-libs/libdvdcss-0.0.3.3 )
Please see Bug #38, too
*** This bug has been marked as a duplicate of 38 ***