i also followed the very confusing informations here:
http://emartee.com/product/41540/MP3%20Sound%20Module%20Mini%20SD%20Card
and used this test sketch with the appropriate AD4 sound file loaded on the microsd 1gb card and named 0000.ad4
http://yapan.googlecode.com/svn/trunk/arduino/examples/SOMO_14D_Test/SOMO_14D_Test.pde
but it keeps silent