DI-624 wireless and gigabit router

Have you tried a direct connection to the PC on which you are trying to play the music? Years ago when I got my first NVX to upgrade from my NV+, I was immediately impressed with the write to speed, but a few days later apalled at the read from speed (at time less than 1kB/sec). Using the above guide to which I was referred by several members, I determined that it was not the NVX nor the cable. Through the process of elimination I determined it was the switch (D-Link DGS2205) which was somehow incompatible with the NVX, but worked fine with the NV+. I replaced it with a Netgear GS108 and have not had a problem sinces. (I did not directly connect to the router for it was at the time a Linksys WRT-54GS with 100mb/s ports).

If the problem goes away with the direct connection, then you know you have a problem somewhere in the network. You then add the elements back one by one until you find the one giving you the problem. In the initial test, I would test the connection with the cable you intend to use between the NAS and the switch, then the cable you intend to use between the switch and the router (if possisble - I recognize this may be wiring inside of structure so might not be possible) and then the cable between the router and the PC (again if possible). That way you have the cables all checked as well.

Just because you are not seeing problems with other uses on the cables does not mean there might not be a problem. I had a commercially made cable that was giving my problems once and using a cable tester, it had a bad connection on one wire. I replaced one end (50/50 chance) and then it passed. That cable is still in use.