Can you tell us what worked in your setup before?
The 5504 and 5040 can stream from one to another, but they cannot interact with the 4xxx series. DVA replicates some of the functions of a RTV and is recognized as just another RTV on the network, so it is not necessary to share between the others.
You should also differentiate between streaming and sharing. All 5xxx RTVs can stream shows between each other. However, sharing involves a transfer of a show to a different box, and 55xx series RTVs cannot so this unless they are adapted to make use of WIRNS.
3RTV over ethernet + DVA show server over buffalo wireless