You might want to keep AFP (Apple File Protocol) turned off. From my Ubuntu box I could see two network icons for my Synology NAS (as well as other windows machines) which upon checking were for AFP and SMB (samba) network protocol. however the AFP which when turned on through the NAS box was incredibly slow (1.6MB/s transfer speed) while samba was upto 100MB/s. Took me ages to work this out thinking that there was something wrong with Ubuntu.