My network problems with a D-Link DGS-1008D Green 8-port switch and several Dreamboxen (PVR 600 and DM 800SE)
belong to the past.
Both receivers were mounted via NFS on a Synology DS 110j.
With the D-Link Green router is constantly came to dropouts in the recordings and when streaming.
With the Netgear GS108 GE Gigabit copper switch now can easily 2 HD recordings are made at the same time and at the same time a movie to be streamed without it comes even to the slightest misfires.
My conclusion: rather invest a little more and save yourself a lot of hassle.