I have the same issue with my DNS-323 and Seagate FreeAgent Theater+. If i try to stream HD video via USB from FreeAgentGo HDD or from notebook via 100Mbit Ethernet - all HD content plays good. If HD streams from DNS-323 via LAN we can have an issue with sound in some cases.
I think, it's an issue with access and transferring 2 files simultaneously: video stream file(1080p) and audio stream file(with bitrate 1500kbit/s and more). If content packed in one file (.mka or .avi) we have no any problems. But if soundtrack stream store in selected file then the SAMBA on DNS-323 not ensure the needed stream transmission(QoS).
I tried to stop additional services(BT, ftp, etc.) on DNS-323 but can't eliminate the problem with sound track. Therefore it is not a CPU of DNS-323 performance issue. Bad multitasking SAMBA?
I tried to use NFS as an add-on service with the same result. Bad multitasking in NFS service?
I dont know
