IIs the music on the same network as the ARQ? If so, dont use PC transfer, but use SAMBA instead. Im pretty sure you cannot transfer playlists, When you PC TRANSFER an album, it will get sorted automacily and placed.

Make sure thou you are not trying to pass "PURCHASED SONGS" from Apple - They encode the purchased songs and cannot be transfered or recongnised on the ARQ - the ARQ just deletes them. If they are purchased songs, you need to convert them to MP3 and burn them to a disc, than pass the music from the disc into the ARQ via SAMBA or PC TRANSFER.