Recently when I play MP3 files, there is sound only on the left, but not on
the right.  This is true whether I use WMP or RP software.  I tried upgrading
the audio driver, but then neither player was able to play at all, so I
rolled back but still have the original problem.  I checked the balance; it
is centered.  I tryed playing the system . WAV sounds; they are also only
heard on the left.  Of course, I checked the earphone on my portable MP3
player; it works fine in both ears.

Does anyone have any other ideas what I can check, to get stereo sound
again?  Thanks.