[Rmp3 & WiFly] Startup Issues

Hello,

The Arduino Uno board does not seems to start up when I use it together with the Rmp3 and the WiFly. When the board is powered via the adaptor, I always need to press the reset button of the Arduino in order my sketch to start and playback an audio file. When I use the USB cable (and the Serial Monitor), everything works fine. Probably because the reset command is called after uploading the code or opening the Serial monitor. I upgraded the firmware of the Rmp3 (http://www.roguerobotics.com/wikidocs/rmp3/beta/start. This seems to help when the Rmp3 is the only shield connected to the Arduino. But when I add the WiFly, so physically (not SW-wise, constructor and init calls), I have the same issue.

Any idea why this may be? or how to debug ?

Thanks