well i m also using nwe005f with sonicstage 4.3 and no problems i also dl it from net. and when i plug my nwe005 and transfer my whole mp3s to it without any problem. i think the problems lies some where else. well u should try to format the player by palyer menu. and then first uninstall ur sonicstage. and then u should remove any hidden files of thw software. in c program files\common files\sony shared as wel as c:\application data\common files\sony shared etc well u should each and avery thing form u r harddisk. of sony software. and then u should install the fresh install the software form cd or net.well mine cd is out of order so i tried the software direct from net and transfering is a breeze for me.no problems at all. and enjoy my nee005 f daily. and loes it.u should not return iit. nwe005f sound very good like an hifi...and the best value for money well u should also try disabling antiviruses and antispywares when transfering music to player