I'm not sure if this is helpful if you are exporting to itunes, but I had a recent problem where nothing would export to a raid device, although it would go to a folder on the desktop (Mac). The problem turned out to be the the choice of export format in setting up the folder. It would not use "export format" but once I changed to "native format" everything worked perfectly, even thought the file formats that I was trying to use (FLAC) were identical.

Ross.

Control:15, TwinStore 2GB*2, 500, Auralic Vega, Pass XA60.8 x2, B&W 802D, Stax lambda & SRM-T1S, Prime Headphone Amp., HiFiMan 500