Your player is flash memory whereas mine is hard drive, but I think there should be a way to reformat your player in its menu. Have a look in the manual or just check your menu. If all else fails there is a plugin available for Winamp that works with Sony MP3 players, however it is only at beta stage of development but might be worth a look instead of using Sonic Stage. Read about and/or download the plugin here:
http://www.atraclife.com/forums/index.php?s=affc67b1791b26ea7be1e3c40b71a182&showtopic=1528