[Mark McLeod]

This is reminiscent of a problem from a few years ago when a race condition was identified between the bridge/router and the cRIO when they come up together.
The cRIO sends an arp hello, but the router isn't ready to receive it. They both are left waiting for the other one to speak first.
The router then won't forward traffic destined for the cRIO, because the router doesn't realize that the cRIO is there (no arp table entry).

That problem was worked around by having the DS force an arp request for the cRIO, so the router would snoop it out.

Another test I'd suggest is to pull the DLink power cable out, then cycle the robot power, and reconnect the DLink power after the rest of it is up and operating.