I've always used a thumb-drive. It's got more than enough space for the music I frequently listen to. Not sure about the larger portable HDs. The thumb-drives and portable HDs may require different drivers in order to be read properly and that may be the issue. Hope you can figure it out man.
Sent from the future.
2012 Kona Blue 3.7L V6:
Borla LT headers, O/R h-pipe, Borla S-types, 3.73 gears,
Steeda adjustable UCA w/ mount, BMR LCAs, Airaid CAI,
LCA Relocation brackets, AE driveshaft, GT 80mm TB,
Black 18x9/10 2010 GT500 Wheels w/ Nitto NT555s,
Eibach Sportline Springs/shocks & Koni STR.T Struts