Just as a note for H10 users (and Sandisk users, though I've already covered that, and possibly other device users as well) for software controlled USB, the VID and PID mode can differ depending on what mode the player's in. See the Sandisk one which has the same VID, but different PIDs for UMS, MTP, and Recovery modes, or the H10 which apparently has differend VIDs for MTP vs UMS (UMS has a Portalplayer VID, while MTP has an iRiver one).